DC Universe Online's revamps of the Mental and Gadgets sets are a case in point. According to system designer Jesse Scott in a recent update on the revamps, these two sets both had several options that felt redundant and fewer unique abilities, so the design team has gone back to the sets improve overall utility and provide more interesting choices.
Mental's core issue was a serious weakness in the Illusions tree, which was addressed by ensuring that more powers in the tree can do damage without relying on fragile interactions. Gadgets, meanwhile, had far too many powers that were doing essentially the same thing. Some powers have been rolled together, new powers have been added, and a few have been changed in form but not in function to address thematic concerns. Even if you've never been fond of these powersets before, the updates might be enough to pique your interest after all.