I really don't think they're a bad company or have a bad reputation. As far as I'm aware, they make the best spinners around. Granted Whirlwind at Camelot is a bit rough, but don't forget that this is a traveling model, and I actually really enjoyed the first drop. Sonic and Crush are pretty good too, although I believe that the majority of Crush's appeal is the theming and the fact that it's enclosed in darkness which adds a new level to the spinning coaster norm. These are the only three Maurer Spinners that I've been on, and I can quite happily say that I've enjoyed them all. Again, I've only heard good things from the likes of Fury and Winjas.
I've been on one of their "Classic" Wild Mouse coasters, which was Wild Mouse at Flamingoland. Not much to say really, it's a Wild Mouse, but it's good at being one.
G-Force is the only other Maurer that I've been on, and left me thinking "What the hell was that?!" It's far too short, too stop-start and doesn't really do much of anything, apart from the novelty factor of the humpty-bump lift. That being said, it does well in the space provided, and is much better than Klondike Gold ****.
Their rides seem to do well in the scenario that they're put into, so I don't really see what the problem is...