Pros: Works great.
Has its own cooling fan!!!
Installs fast.
Not a plastic cheap one.

Cons: Not free lol.

Pros: easy to use

Cons: heat transfer

Other Thoughts: Purchased a pair so I would have one for a backup in case the first one failed and it did. Just over a year and the ejection assembly is a waste case. My customer uses this a lot, but I would expect a few years out of it anyway.
Note: I installed the second one yesterday and the SATA power plug did not work. I had to use the Molex to get the hard drive to fire up. Not good as this one was NIB.

Pros: Solid construction and amazingly easy to install and use.

Cons: A major heat problem. While the fan works, inserted hard drives fry (+50°C). I have used this device in multiple ATX/mini-ATX cases and I am at a loss. Thus, I use it like a floppy drive for hard drives and limited use, definitely not for large file migration or backups. An USB adapter and a large fan works for me on these longer operations.

Other Thoughts: This is a great idea that has yet to work well for me.
As for Newegg, well they get 99% of my orders. I think that speaks for itself.

Pros: Wow! How come nobody invented this product before? I love the way you can stuff any sata drive into this thing with no power or esata cable to mess with. Abolutely brilliant!

Cons: Others said that the fan still worked even if there is no drive. I can let that slide.

Other Thoughts: Gonna buy 1 for each pc we have.

Pros: Simple to install, well designed with good materials. No caddy required - quick to swap/replace drives. Case does not have to be locked for drive to work (this is both a pro and con). Locking only prevents the drive from being opened/removed.

Cons: As first reviewer mentioned - fan stays on all of the time. It should only be on when there is a drive inserted/locked. Better ventilation with vent holes.

Other Thoughts: Great price and implementation. I've used for 2+ months and am buying more.

Pros: High quality of materials used. Convenient tray-less design. Better designed and built than others of this type.

Cons: The fan is on all the time, even when there is no drive in the rack. The key lock doesn't turn the fan on or off (even the cheapest plastic racks have this feature). So the fan on the unit I bought crapped out after about three weeks of use.
The HDD is insulated from the rack via the suspension mount so there is absolutely no heat transfer between HDD and rack. Thus you really need the fan when the rack is in use.

Other Thoughts: They could have punched ventilation holes on the top of the steel casing to aid in cooling.

Pros: HDD access LED works, looks good, no drawer. Most of the mobile bays I looked at either don't have a HDD access LED or require that you plug one into the motherboard headder. If your like me you already have something plugged in there. This one just works all on it's own. It looks great and you don't have to buy a collection of extra drawers to change drives. Just stuff a bare sata drive in and it works.

Cons: Small fan, no drawer. The fan is a little small and I don't think it does much. My drive runs about 2C hotter than it did when mounted in front of a 120mm case fan. It doesn't use a drive drawer so you have to be careful with a bare unprotected drive after you remove it from the rack.

Other Thoughts: I love mobile drive bays. For years I have used them for backup. I use disk imaging software like Drive Image to copy my C:drive to a removable disk. This way I always have a copy of my computer stored away from my computer. The fact that this unit doesn't use a drawer is both a plus and a minus. The plus is that you don't have to purchase extra drawers. Some racks don't even offer spare drawers so you have to buy entire racks just to get extra drawers. On the other hand with out a drawer the drive is unprotected after you remove it. It would be nice if someone sold a cheap little padded box to store the removed drives in.