Dive machines are really boring once you've ridden a good Intamin. I went to Williamsburg right after Cedar Point, and everything except Apollo's I found highly uninteresting.
Hypers are all good and well, and I LOVE Giga's, but another Maverick-esq coaster at KI would make it a lot better.
THEN, they should take Vortex (Which I find quite painful, but I've never ridden SoB, so I guess I don't know the true meaning of painful) and use it's track design to turn it into an Intamin. Then, it would be smooth but you could keep the safety and smooth-ness Intamin's offer.
I do agree that they aren't happy with maintenance, but frankly it is on the park to keep the rides running, not the coaster maker. Six Flags is terrible at everything Amusement-park oriented, (safety AND reliability) so I don't blame Intamin for anything that has happened on one of their rides at a Six Flags. Safety is all a matter of the ride operators, not the ride. If it offers good restraints (which Intamin does) and there are good operators working on it (like at Cedar Point), Intamin rides are REALLY safe.