Bought the Define XL in February, I like the case but I had some issues.
My PSU corsair 520W doesn't fit, I dont know why but the only 3 screws line up and i had to put a bit of cardboard under it because it only sits on two of the 4 rubber feet in the PSU section. So not a deal breaker but it was frustrating especially since the psu is pulling away from the case.
Also be careful make sure you get yourself an 8-pin extension for CPU power, unless you know your 8-pin is quite long, ebay do it for quite cheap. A 24pin extension isnt quite necessary unless you know your 24-pin is quite short. Get some cable ties for cable management, but around 6 are provided with the case.
There is enough space for 6sata and 6hddpower cables, 24pin,8pin 2pice 6pin and other small cables in side, which has about 1inch of space.
I put a fan on front-bottom to cool my 6 HDDs but it only cools the first three HDDs at the front, the fan air doesnt reach the other 3 HDDs. Also there is a really really annoying pulsating feeling that comes from the case, this is because of the HDDs. I cant hear or feel it much when sitting at the desk but sleeping 7 feet away I can clearly hear a pulsating noise. I tilt the case and noise pretty much gone, I'm thinking of raising it but putting some dvd cases under it.
Really thats the major stuff, clearly stock fans are not nearly enough. I've added two intake fans at the front to make a total of 3.
So temps are pretty decent and noise level is OK i guess. I would say it was very slightly better than my previous Antec 900, though the Antec did cool all my HDDs and there was no pulsations from the case. However it has load more cable management options and dust filter, though not all removable, so in that sense its better.
Overall Im happy with it, just need to sort out the pulsating sound, anyone got any ideas?