I currently have the Antec 902 v2, I feel that the uneasy access to Hard Drive Bays and the fact that I cannot open the top section of the case to access the fan has run its course with me.
Whilst investigating on the internet and viewing youTube PC build reviews, I came across the Coolmaster HAF XM and found that I liked the nature of accessibility of certain features the case offers. But I have yet to find anyone who has one or seen first hand whether it is a good replacement for my current case.
I don't personally have experience with the XM, but I have the HAF X. The HAF XM is basically just a shrunken version of the HAF X. I actually originally wanted an Antec 1200, but I found that it wasn't going to supply the amount of space I wanted, and it also wouldn't be able to fit an H100 in it.
I love my HAF X though. It's got a lot of space to work with and the steel is thick and sturdy. The side panels never bow out or anything, and there is plenty of room for cable management, long video cards, hard drives, and any sort of cpu cooler you want to install. I would imagine that the XM is just a smaller version with a couple of updated features, so I would imagine it being a very nice case and a lot more versatile than an Antec 902.
I love both cases personally. Back when I was building my pc a while ago I was having a hard time deciding between the Antec 1200 and the HAF X. I when with the antec. I think for my next build I'll go with a HAF case, the red LEDs are pretty damn sexy.