I've got three of the HAF 922's, and really understand what Charlie98 is sayin' there.
I wouldn't say my relationship with the cases is a "love-hate" conflict, but he has a point about the dust. The front-intake 200mm fan has a wire-screen filter -- a little troublesome to remove and clean. The side-panel 200mm has no filter.
I can see the trend is going to smaller cases. I also see that some folks might even imagine they can build a PC without the traditional airflow. But with water-cooling, you're either going to try and put water-blocks on every-freakin-thing, or allow motherboard components to get warmer than they need to -- unless -- unless -- you bow down to the airflow imperative.
I have a sweet-tooth, occasionally, with less of an appetite for cakes and cookies than I did when I was younger. I've noticed the grocery store sells their cakes in these clear, round plastic cake-boxes. So I have this inspiration that I can build a low-profile external retainer for a circular (200mm dia.) piece of your standard $2/panel fiberglass AC filter. I just need a way to elegantly affix one -- perhaps 1/2" thick -- to my sidepanel.
I think it's going to be easy. Once a month, I can remove the filter (easier than the front-panel HAF filter, for sure!), put it on the patio and blast it with a hose. It doesn't offer anything in the way of "bling," but if it's neat, if I use the white fiberglass option, it should work -- I think.