I’m a HUGE fan of dynamic cloth… even to the point of using it for things like socks and pantyhose because it looks more realistic.  But I’m still one of the ones who cannot use it in P7 (even after the SP1 upgrade).  Either very few people are pushing the cloth room as hard as those of us with the problems, or it is just a random problem with specific computers.  Either way, be warned that you may have a really bad time with cloth in P7SP1.  Even on very simple animations I have fall through and figure explosions.  Very annoying.