I've been putting off getting one of these since buying my Antec Twelve Hundred. The time has come since I've reached the 3.5" slot limit of the case. This cage fits in (3) 5.25" bays, which is perfect for the case since it uses slots of 3 for the default drive slots. I did have to modify the case to flatten the guides that typically hold each slot. I had to go and get a deep jaw c-clamp to flatten the guides.
The overall install is easy and the drives went in snug. The temps I were getting in this cage versus temps in non-compacted slots were about 10-15C higher. The 7200rpm drives maintain a 46C temp while my 5400rpm wd greens were getting 42C.

Overall though, the best cage to maximize disk space on the twelve hundred. As time progresses, I will eventually buildout the case to have three more of these.

I have owned this just under a year, It is nice to have the ability to swap drives in my server without taking it apart. Unfortunately I have had issues with a specific drive slot that keeps going off line (swapped drives/positions). I'm not sure if I have a lemon but it's not something I can just return to amazon since it's still in use on the server. I will need to replace this with a different brand.

When I install it in my PC, it makes it look cool. Makes your drives easily swappable, even hot swappable if your controller supports it, which most SATA controllers do. Lets you see which individual drives are being accessed with the front viewable LEDs.
I had to bend down four metal tabs in my PC case to allow this to fit, wasn't difficult.
I loaded mine with five WD Blacks and set the 60% fans speed jumper and with the computer in a pretty warm room and the drives mostly idle, my raid card set off a temperature alarm when it detected that 3 of my drives were above 60°C. Raised fan speed to 100% and even with all drives working hard, they stay below 60 (my raid card doesn't let me see what temperature specifically). Fan noise isn't too bad.

Dead on arrival: fan doesn't spin, no load on disk.

That aside, this whole thing looks solid at the first glance, but its not particularly useful.
- There is no opening on the cage to accommodate case guide rails, so you have to bend or cut the guide rails on case in order to fit this cage. (can you believe that's not actually the reason for return?)
- Fan is much smaller than other units, so even though I didn't actually hear it, I can imagine it to be loud.
- The connectors on the back side are all over the place - on three of the four sides. Again, not very convenient for installation (that's after you bent the rails of the way).

Rosewill 3 x 5.25-Inch to 4 Drive Cage on the other hand is not as pretty, but much more functional.

Update:
Attempted to return, seller refused.
It took me over 30 days to get all the parts, so I didn't find out it's dead until after I powered it on. ICY DOCK declined return (yes, it's my fault on the timing, but come on! Stand by your product!)

ICY DOCK FatCage MB155SP-B 5 Bay EZ-Tray 3.5"

Arrived on time, Excellent Product, works great, Easy setup, Will Buy Again... Fast Shipping.