I'm using the WRX kit and am going for a full indash setup, but if that weren't around I'd be straight onto something like that.
Infact, after seeing that seconnd tier you have put in above the mobo, I'm thinking that might be the way to go for to mount my HDD and m2-atx.
Have you had any issue with heat? Just on the bench my whole chassis is getting quite hot, but no more than the stock headunit does at the moment in the car. That second 'level' might help me mount a fan in the somewhere to help with the heat.
I reckon quite a few people would be keen on that as few people have the knowledge and resources to do it themselves. Even if they don't go for a full indash setup like you and I, they will still have a nice solid chassis to mount their screen on and anythign else that doesn't need easy access (PSU/SDC/HDD).
Would you pre-drill the holes for the most common components? (the WRX kit has the holes pre-dilled to mount the M10k and any other mobos with the same mounting points)