Actually, you can get quite a few advantages. You can have strings/ties that move in animations. You can have underwear that give natural stretches and folds.

I absolutely disagree with you Afrodite.

Take for example a pair of tights. When they stretch over say the butt, it creates a stretch, with creases that changes naturally when you move the legs into different position, something that is much harder to achieve with conforming clothing. Even tight clothing gets creases.  I use almost exclusively dynamic clothing, not out of laziness, but because I get results I find to be far more natural looking. It can look absolutely amazing. 

With tops like tight shirts you can get a perfectly natural spandex effect on breasts, or stretches resulting from muscles and arm positions. Some conforming clothes have creases built into them, but they don't adapt naturally to how the figure moves.

I've got all sorts of dynamic tight clothing and usually prefer them to their conforming counterparts. 

Anyway, that's my experience on the matter. I definitely would not discard using tight fitting dynamic clothes. :)