well that's basically what I was asking myself too a few months ago. He's been exclusiv to Hospital for about half a year (actually after releasing Stars Get Down & I Need You on future sounds of russia). Then he uploaded an amount of stuff on soundcloud and a few months later (I think it was about half a year) he was exclusiv to Metalheadz again.
He's got an amount of tracks to release and working on an LP for Metalheadz now and @ Tiesticles, I don't think subwaves style would have really changed of if he were signed to Hospital. He's done quite a few cheesy tracks i.e. First Time which was released on Headz... and the new bits would suite both labels perfectly IMO just that his stuff is way better then the cheese any of the hospital heads would come up with. (I do rate Logistics & Nu:Tone tho always come up with something different)