Second choice (This one is lacking more on features but I enjoy the look and ease of use on the front fans and drive bays. Not to mention it's an upgraded version of one of the greatest cases of all time, The Antec 1200.)
I would go with the HAF X over the Antec DF-85 (owner of an Antec 1200).
Since you are a fan of the Antec 1200, you could look at the upgrade new Antec 1200 V3, which has better cable management features. Antec 1200 V3
I do like the Haf X more than any other, but the window on it is technically useless as it only shows your drive bays. However, the Antec 1200 V3 has a large window cutout and a side dust filter over the DF-85 but is lacking a side fan. I'm probably going to stick with my original choice and get the Coolermaster Haf X. Thanks for your opinion!
I just had to make this tough decision myself. My three were the haf x, the antec df-85 and the corsair 600t. From my research and YouTube vids I ruled out the antec, the individual 5.25 drive bay doors seemed really stupid. Granted it looks good, but would ultimately just be annoying. So it came down to the haf x and the 600t. I like cases with windows but where I put my tower the window is covered by the desk anyways. Both cases look cool, but the most important thing for me was cable management which both do well. Reviews of the antec stated that although it was designed for cable management it was very difficult or impossible to hide away the 24 pin mobo cable correctly. For me it came down to price and quick shipping. I have an amazon prime account and most products amozon stocks ship 2 day free and next day shipping is just 3.99. I needed my case the next day for my build and amazon had the corsair and not the haf x so I went with the 600t and have absolutely no regrets. I know it's technically a mid tower, but this thing is a massive mid tower. My previous case was a gigabyte aurora full tower case. The corsair is about an inch and a half shorter, but it's wider to allow for it's excellent cable management. This case feels so much bigger than the gigabyte case. It has excellent airflow and it looks so much better in person. My only gripe is the with the hdd trays. They are made of plastic and seem a little flimsy, they haven't broke though. I was really torqueing on them and they didn't show any signs of stress, so they may be just fine as I haven't heard any complaints of them breaking.
Anyways if it's between the haf x and the antec I would go for the haf x. You may also want to consider the corair 600t it's a great case and a little cheaper($159.99), but if you want a huge case obviously the haf x is the way to go.
Go alluminium! If your gonna pay $200 for a case your better off going alluminum imo. The quality of alluminum cases especially the Lian-li cases are amazing. I got the Lian-li 7FWB and i gotta tell you it looks a 100x better in person. I've looked at the Coolermaster HAF X and that Antec case and i gotta tell you i wasn't impressed with it at all. They just feel so cheap. Only case i like that's not alluminum is maybe the corsair 600t and the NZXT phantom..The NZXT phantom looks ugly in pictures but in person it looks pretty good. But then again it's plastic so i ended up buying a alluminum case and went with Lian-li.
Here's the one i ended up going with... along with the top cover i got with 2 140mm fans.
so it cost me $185 not including taxes. But ended up getting a roomy mid tower case with all the cable mgt holes and the best part was it's all alluminum. Big enough to fit 2 GTX 580's in sli.. Hope this helps..