As someone who has an aluminum case with much thinner panels than this one, I'd have to say durability would be one. My lian li case managed to get pretty banged up with normal use. As soon as I saw the panels that he was using, he just sold himself another case whenever he can make more, lol.
I've been looking for a case like this for so long that I was getting ready to build and design one myself! Roughly how heavy do you think the finished M3A2 case will be?