i have some 15mm Seagate enterprise 2TB SATA drives that went right in with not trouble. The all-metal chassis and rails will likely wick away heat and the fan is not too loud. An SSD I installed into one of the slots runs at the full 6Gbps speed. The amber access color on the front LED is subtle but welcome. The enclosure is SAS comparable though I wan't able to test that. The only thing that would have made this better would have been tooless sleds or no sleds at all. This thing is only $5 or $10 more than the cheap off-brands. Trust me - get the good stuff and you wont have any problems. ICY Dock also sells 6 and 8 bay enclosures for thinner drives. Recommended.

Freaking awesome. I have a full tower case. In these days of tiny little wimpy cases and itty bitty laptops, it's nice to own a mid/full size tower case full of drives, with six fans pushing air through and lit up inside like an Xmass tree. I have room for six hard drives, 2 DVD/Blu-Ray drives, and my XM radio. BUT - alas, the relic of this older case was the 3.5" floppy drive, whose only function was to plug a 3.5" hole, as the bezel cover was long gone. What to do? Leave the ancient drive sitting worthless in the front of the case, hogging valuable room? NO! Enter the ICY DOCK 2.5" drive holder. Removed that old piece of crap floppy drive, and bolt this thing right in. Gone is the diminutive 1.44MB drive, and in it's place is a slot capable of holding a 2TB SATA drive. Works just like high-end server drives: push the button, grab the handle, and pull the drive from the slot. GREAT for backup drives. Right before vacation, just pop out the drives and leave them in your desk at work in case of fire or burglary or the rapture. You'll have all your stuff when you get back. Flashing lights when in use make the computer even more cool and nerdy. Ordering a second one to replace my other 3.5" cover currently covering a space occupied by an old 250GB drive.

The case and trays seem well constructed and fit perfectly in my case, a Fractal Design Define R5 Silent Mid Tower unit. The trays open and close smoothly and slide in and out without any drag or speed bumps. You also get a positive click when snapping the door shut. In my case the screw holes in the cage lined up properly but the bottom front hole on both sides was obstructed on the inside so I was only able to use three screws on both sides (2 rear and 1 in the upper side in the front). However the cage is secure and tight. No problems.
I can't comment on the fans as I have only SSDs installed and have them turned off.
I read quite a few negative reviews regarding the short screws and improper fit of the drive trays. I'm glad I took a chance and ordered this as I've been very happy with it up to this point.

First off, great product. Wish I had found these sooner. Hot swap and two SSD bays, awesome. As per my title, individual additional trays are $16 or so, and this product comes with 2 trays for around 30... so you are better off buying this with the 2 trays in it than buying two more additional trays separately. At least you can either have a backup plane should you need it, or put it in a second machine and swap SSDs around between machines if that makes sense.

Pros:

All the mechanical parts are metal which is a big plus. They're somewhat flimsy but a lot better than the cheap plastic of thermaltake
Good solid rear connectors. Cords fit snugly into the SATA ports and power doesn't feel loose at all
No vibrations from the backplane that I can tell

Cons:
LED flicker from drive use is almost impossible to see. The LED's stay lit for a much shorter time with a much dimmer yellow than the thermaltake
This might sound minor, but when trying to identify a dying drive "blink" apps likely won't work on consumer SATA drives so you're going
to rely on off-lining a specific drive then watching for which LED isn't blinking under heavy use (such as a zfs scrub)
Bay is very short so it's hard to reach in past other components in a standard case to plug the cables in (one-time issue during installation)
It's fairly easy to accidentally hit the latch release (My cat has done it by headbutting)

Overall I'm a lot less worried about breaking this than my thermaltake, however the thermaltake is easier to install and I like the intensity and duration of the LED's on it better