Full disclosure: I have not used a Haf, I own an ATCS 840.
My take is if you want a case that has all the really nice features (ie removable mobo tray, extra large fans, dust filters, WC ready, cable management) but dont' really care about bling, you will love the ATCS. If bling matters enough to sacrifice some features and save some money, then you will like the Haf better. Worth noting in the bling department, you can purchase a side window panel for the ATCS for ~$40.
As far as cooling, I have not had any issues with temperatures on my i7 920 running at 4GHz with a TRUE. I also run a 4870x2, but it has an aftermarket cooler so it's temps are really low. If you think temps might be a problem for you, I think it's pretty clear that the Haf has more raw cooling for CPU/GPU thanks to its side panel fan, the ATCS cannot compete with that.
A few key features of the ATCS that stood out for me:
The removable mobo tray is awesome, put simply. The entire backplate of the case pulls out on rails with ball bearings very smoothly, so you can put all your CPU/heatsink/ram/pci cards in, then slide the sucker in and connect the cables.
The case is clearly built with cable management always in mind. The mobo tray has cutouts for the PSU power connectors so you can route them behind the tray and have them just peek out the holes and plug in (this could be an issue for some PSUs with shorter cables. For reference, I'm using the Corsair 1000W). All the cables for hard drives connect on the back side of the case, so you don't see them if looking in through the left side panel. You will also find pre-installed cable tie-downs in the back here to tame the cables, and the case comes with several extra tie-downs if there are other places you want them.
The pop-up connector panel on the top of the case feels extremely sturdy and I doubt if it will ever break. It also has extra space between the USB ports so that 'fat' usb connectors can fit side by side.
The hard drive mounting system is super-slick (I believe it's identical in the Haf?) and seems reasonably sturdy. The 5.25 mounting system is certainly quick, but leaves the drive a bit loose in there.
Obviously, all the room you could want.
The drawbacks I encountered are as follows:
The default airflow setup is questionable. Two 230mm fans exhausting at the top tend to steal much of the fresh air from the frost 230mm intake. On my case I have the front top fan off ATM, even though in doing so I saw no significant change in load temps (1C maybe). Changing this front fan to an intake may improve cooling.
Mounting a fan on the bottom of the case tends to end up with part of it rubbing on the case while running, making loud noises, so you have to find a way to stand it off a bit from the case (I just used a small washer on each screw).
When a bottom intake fan is installed, you cannot remove the dust filter for the PSU without removing the fan.
The panel covering the front 230mm intake fan is apparently tricky for some people to remove (I had no problem with it).
As on some cases, the HDD and power LEDs on the top of the case are extremely bright. I have my system on an night and it's up on a table, so the lights shine right to the roof(they point straight up from the case). I had to disable the HDD light because the flashing could be seen while looking in any direction in the room in the dark, and was distracting while trying to go to sleep.
I rather enjoy the power LED staying on at night though, just enough light so you can easily make out all the hazardous objects on you floor on the way to the bathroom at night
![:D :D]()
.