From what i gather, everyone's main comment/complaint on stealth was the lack of major flying time ( when the trains flip so you fly like superman). Why hasn't a company mad an inverted coaster where that is the default position? It seems like something B&M would do, changing the trains on inverted track...
Also, there has been some talk recently about bobsled coasters, and a couple of years ago i went to lake placid NY and they had the olympic bobsled run running with the bobsled cars out fitted with wheels. That was a pretty sweet ride, actually, the entire thing is down hill, so you keep going faster and faster, all in all, quite a rush