I find that the fitting room performs best if I devote the time to fitting a garment first with posing, built-in morphs, and the morph brush. I almost never use the auto-fitting in the fitting room so I can make sure details aren't destroyed. I convert using the rigid features selection instead of tighten if I want a slight nudge with the auto-fitter (and I concur that 10 is about the max number of iterations before distortion occurs). The auto-fitter also can rip apart poorly made garments, and if you do the work yourself up front, that won't happen.

Does Crossdresser leave ghost bones like skirt handles intact?