In my experience, the Tailor is really great, but doesn't work all the time. It's good for quick jobs but depends on the clothes being morphed. Changing the polycount is all right, but you'll loose any mrophs already existing in the clothes. On the other hand, if you open the clothes' obj in a modelling program, you might just as well do the morph in this program. The results would be much better. If you're planning to use the same character over abd over and want different clothes to fit better to her, then you may consider using magnet sets instead.