How bad typically is the render time anyway?

No slower than the render time for conforming clothing. But the Cloth Room setup process, where you run the cloth-sim calculations prior to rendering, adds some time to any project.

i want to watch animations made using poser(and other soft as well) so if you know any good site with lots of good or bad animations, tell me please...

Good animations:

www.belino.net, the home of Philippe Bouyer (Phoul)
www.changestorm.com

Bad animations:

Disco (MPEG format, 3.2MB)
Hula (MPEG format, 869KB)
Mimic Wolf (MPEG format, 556KB)
Cloaking: Low-Res Edition (MPEG format, 5.9MB)
BulletTime (MPEG format, 873KB)
Music Box Dancer (MPEG format, 5.24MB)