i'm not sure i understand what good and bad UV mapping tools even are.  i certainly haven't gone beyond trying to map stuff.   but the things i appreciate so far about Blender UV mapping (at least as far as i can tell) are that it seems pretty easy to mark and set seams, subdividing to add more polys doesn't seem to change the mapping, and the options for types of mapping seem pretty good.  i think i've also read that Blender has mesh painting tools.