Only problem for me is that I'm not sure I'm into the cube style. The 540 looks nice but can't help thinking it will look a little daft on my desk. I'll definitely consider it though.
I've also been looking at Silverstone cases as they're meant to be pretty top-notch in terms of build quality. I stumbled across the FT04 and though that could be the one. Great looking, supposedly great cooling too, but then I read about problems with a weak magnet for the door and poor cable management.
Also looking at the FT02. Just can't make my mind up...