I can see both sides... but I can tell you that it's definitely easier to learn momentum driving in a car that requires it. If you can rely on power to make yourself "feel" fast on the track, you will. If the only real strength a car has is it's handling capability, you must learn to use it. The clincher is that once you've learned to see and drive the most efficient line all the time (because you have to), you can then apply those same skills to any car... like, say, a faster one.
Jeremy... what "fast car" did you learn your basic autox/track skills in? Didn't you learn in a momentum car?