Pros: Excellent speed. Replaced old WD Nas devices - dramatic improvement!

Cons: None so far

Other Thoughts: Highly recommend these - not one issue so far. Remote access flawless, join to domain flawless, set up flawless.

Pros: OS is easy to use, lots of apps for the device (FTP, Cloud, bitTorrent, Video Station for software specific Media Stream, Media Station for generic) Bondable NICs, USB 3.0 on board. Free DDNS from manufacturer so you can host all of this on the internet.
I've got friends and coworkers asking me about this item

Cons: Price, really the only thing slowing my friends and coworkers on picking this up

Other Thoughts: Slightly more suited towards SOHO and Small business. Mail Server, All sorts of programming language apps server platforms, as well as a few Business apps (Accounting, HR, and warehouse management types)

Pros: It works. Pop the discs in, use the interface to configure the storage and watch 'er go! The web browser interface is fairly intuitive after only a short time playing around with it. There is also a good user support base on their forums. You may not find all the answers you want, but they will point you in the right direction. And this was all from reading previous posts. I didn't have to post anything to find what I was looking for.

Cons: If you search for "synolock" you will see that Synology had a major problem with their NAS's getting hacked. IMO this was largely due to people not protecting something exposed to the Internet. Nonetheless, Synology put a LOT of security into the new implementation of their management software. For those of us who are tech savvy with linux, this stuff really just gets in the way. It took me a long time to figure out how to map the shares on the NAS to my Debian and Mac computers. And even now, the permissions are not quite right. I'm sure this is fixable, I just need to spend a lot of time learning even more about linux to do this...kind of annoying.

Other Thoughts: It appears Synology really has fixed the synolock issue. But, word to the wise, do NOT put any computer system onto the Internet unless you have it very well protected. In linux land, this means setting up SSH to only use public-private keys and disabling password login...passwords are guessable, private keys are not.

Pros: The DSM interface!
Product quality
Noise level
Low heat
Number of bays

Cons: Price
Took a drive out and put it back and had to reinstall DSM. Lost permissions and users and other settings, but data remained intact.

Other Thoughts: You CAN'T GO WRONG!

Pros: Small, powerful, full-featured, expandable, quiet, easy to use, fast. The software alone that powers it makes it worth every peny. Want to run a web server, mail server, your own media library (with Plex, DLNA, Media Server), Dev/Ops tools (Gitlab, Jenkins, mysql, docker), standard file shares. its all included out of the box. Built-in Antivirus, offsite cloud backup capability built in, link aggregation and fail-over for up to 4 ports; what more can you ask for?

Cons: None that I could find and I've had mine since March 2015.

Other Thoughts: For anyone who has a small business, or anyone who wants to have business like features without the big price tag or headache, this is a must buy. The fact that Synology is constantly upgrading the software and adding new features is very impressive. I was shocked when I logged in the first time and found one-button installs of Drupal, WordPress, Joomla, Java, SVN, Git, RADIUS, VPN, LDAP and ERP software to name a few. My configuration is:
- DS1515+ (2 Nics bonded)
- 4 x 4TB WD Red
- Netgear R7000 Nighthawk
- APC Back-UPS 550W
- WD 1 TB External drive connected via USB and shared.
Running Gitlab, Docker, MariaDb, Media Server, Antivirus, etc.

Notes: You want to remember to purchase the drives as it comes without them. I also recommend getting a network switch that supports Link Aggregation (Nic Teaming or the LACP feature in the Newegg search) to take advantage of the powerful network features that are included. An Uninterrupted Power Supply (UPS) is a must as its saved my device plenty of times since I live in an area where they have frequent power fluctuations and outages due to weather and construction. I use a basic APC UPS connected to the SAN via USB and it manages itself and even emails me when outages occur. One feature I'm eager to try is the Solid State cache option and when I add a new server, using it for VMware and Hyper-V. its my own private cloud. I highly recommend it.

Pros: Okay, it is simple. I love the bonding of ports for better throughput. Nice UI, which even my wife who isn't a Network / Storage person could use. She found an app for her iDevice that lets her upload pictures / video to the Photostation add-on. User level controls. Best of all: I haven't had to touch it since setup really.

Cons: Initial setup is slow. I mean excruciating, painfully slow, when you're setting up 5 - 4TB drives in SHR. The bonding is a bit goofy to setup. I left 1 of the 4 NICs with a separate hard set IP for device management, just to be safe, after an initial annoyance.

Other Thoughts: Definitely get the memory upgrade. You'll thank yourself, especially if you have multiple people using it.

Pros: This is a well thought out and solid NAS. This is an upgrade to my older Synology DS410 4 bay model, and it much faster and far more capable. Sync files and photos with your phone. Backup computers around your home/office. Share files with friends and family. Add optional software/apps from the package center. This thing can do prett much anything you want a NAS to do.

Cons: Expensive.

Pros: It's Synology. It's easy to install, it's easy to setup

Cons: None

Other Thoughts: I also own a previous version, the DS1511+. I started to run short of drive space, and decided to purchase another unit instead of just upgrading drives. The improvements over the previous version are noticeable. The better CPU and more RAM lets me get more performance than I was getting (which was already pretty good). 4 Gig NIC's over two is advantageous, as I needed at least 3 (one for iSCSI, one for DLNA service to the user VLAN since it can't be routed, and one for other services). The biggest sign of the upgrade to me was when I did the disk check after creating the RAID array. I have 5 4TB drives setup in a RAID6, and it took about 12 hours to do the checks. The same check on 5 2TB drives in the 1511 took 36 hours. I have been very happy with my 1511, and have no doubt that I'll be exceedingly happy with the 1515. The 1511 isn't going anywhere either, it's being repurposed to an iSCSI only unit so I can separate my VMware storage from the rest of my stuff.

Pros: Everything and more that I could ask for! If you have the money, don't cut yourself short. Buy a Synology NAS, and you'll never turn back. It has the simplest setup, UI, and is the best NAS on the market!

Cons: Nothing.

Pros: Fast setup and simple setup. Update was fast and the 1515+ will beep after completion. About 15 minutes to get it up and running.

Installation of the applications are straight forward, video station does gathers metadata, rating, summary and poster art for movies added. You can play videos from the browser or access the files directly as a network share.

Plex Media Server seems a bit processor intensive on the device but it does work.

It can do link aggregation, bonding of 3 Ethernet ports at this time, so backups, file transfers, streaming/encoding on the fly is no problem with this unit.
Adding an external 2.5 usb 2.0 hard drive formatted NTFS automatically shared the device to the shared network.
The included tools/features/free apps, you can scrub the drives for any data inconsistencies, schedule quick or full S.M.A.R.T scans, security checks such as weak passwords, and virus scanning. You can also do folder level encryption which still maintains fast transfer speeds.

I was able to add a 4GBs ram stick easily, take off 5 screws and cover, just be sure to check you are using the correct specifications, total 6GBs of ram.

The user interface is easily accessible, very smooth and easy to use resembles a Linux desktop.

The build quality of the enclosure is a solid metal with some plastic. The drive caddies are made of plastic and metal latch that is lockable with a plastic key. Plastic retainers on the side snap off and on the hard drives for retention. The caddies also have rubber grommets to reduce vibration or to improve the fit of the hard drives.

Currently using 5x HSTG 4TB NAS which are on the DS1515+ compatibility list. No problems at this time. Configured with Hybrid RAID 1 disk failure for fault tolerance.

Accessing the web or share via Windows or OSX without any issues.

You can expand the unit with 2 or 5 bay expansion bay units from Synology.
2x eSATA ports for that feature or add external hard drives with the 4 USB 3.0 ports. Seamlessly works with NTFS formatted drives.

Cons: Expensive. If you want the most out of the unit, you will need to pay the extra cash for a more capable switch, cat 5 cables only 2 included. The drive caddies could be made of metal, the retaining clips feel solid but I don't know how long they will last due to being plastic. The biggest fear is breaking off a plastic notch off the clip.

The packaging was horrible, the box arrived completely open with the top smashed off and taped back together with clear shipping tape. It shipped in the original box from Synology with no additional protection.

Other Thoughts: I purchased this unit to consolidate all my external hard drives, encrypt personal files, stream music, videos, pictures. I intend to use the USB 3.0 ports for additional backups or removable drives for on the go always synced and up to date files.

I drop it 1 star because the retail shipping box fell apart. When you purchase a product you also pay for the package it comes in, and it falling apart prior to arrival is not acceptable especially for a $800+ unit.