Pros: None

Cons: I bought this to replace my older slower QNAP TS-220 which I have been using a few years as a home file server. I wanted a faster CPU to have encrypted shares to protect the data just in case. I also wanted to do backup of that data to external USB disk.
I set it up and it just doesn't work. The backup logs hundreds of times repeating, hundreds of errors and never completes successfully. Actually now it just runs reading the disks over and over and never ends. I've worked with QNAP to resolve this and after a couple of months of trying its still not working. Unfortunately its beyond the return date.
The only feature I am using is CIFS, AFP and NFS shares with backup to external disk. I've tried all the combinations, encrypted, non-encrypted, upgraded firmware multiple times. Had QNAP support on remote desktop session several times and invested a lot of time and hundreds of dollars for something that doesn't do basic functionality.

Other Thoughts: I would not recommend buying this. Backup to external USB should be a simple basic function of the product. I recommend trying another brand or building an ITX server which should be easy to do at the same price or less.

I wish I would have returned it when it was possible. Now I am stuck waiting to see if someday it will work as advertised.

Manufacturer Response:

Dear Michael B.
Sorry to hear about what you are currently experiencing with our TS-251+, as this is not the intended or typical experience with the device.
We will work closely with newegg team to provide you better shopping and product experience
For your case,
after 30 days of purchase, please contact QNAP technical support directly
we will arrange a new unit for you

If our support team can be of any assistance to you, please contact us via email or phone below and reference this Newegg review.
(909) 595-2782
http://www.qnap.com/i/useng/about/con_show.php?op=showone&cid=1

Pros: Works great with Plex!
Excellent tutorials and apps makes this NAS usable for even a non-Linux user
Highly customizable with plenty of room for future uses and expansion

Cons: None!

Other Thoughts: I bought this NAS after first trying to install Plex on an underpowered server and running into all of the troubles with that. I was nervous about getting into something this high end as I'm not Linux-savvy but I was able to easily set up and load the program and found tons of additional great QNAP apps to expand the uses of this NAS. It's the perfect system for a mid-tech user looking to build his/her multimedia library.

Pros: With its quad core CPU you can use this as an entertainment system, download station and lots of other things, all with low power consumption and without the need for a PC. Of course the NAS gives service to the PC and it does it very well.

Cons: None found yet.

Pros: Easy setup. Quality product. Lots of programs to use. Love the web interface.

Cons: Not really a con but there are a lot of programs available and it's hard to choose what to use.

Other Thoughts: I should have purchased a 4-Bay model.

Pros: Speed/power, cost, pretty easy to learn the software.

Cons: Nothing really.

Other Thoughts: This is a great little NAS. It is serving all of my current purposes rather nicely, with plenty of power for future uses. One thing I'd like to note...NewEgg has this NAS listed as 2.41 Ghz which would indicate that it is a dual core processor. This is incorrect. It is a 2.0 Ghz quad core, as stated on QNAP's website.