Didn't overdo any bad guy. Nice balance of: Romulans, Klingons (for a time), Carddies, Dominion, and a few more. Voyager, drove the Borg into meh category.
I could have done with less Klingon stuff at the time, but these days I've kind of mellowed on them and don't mind 'em so much. I didn't want Worf on my beloved DS9, but for the most part it worked out okay.
The whole Dominion arc thing went on for way too long, after the nice slow build up, the major part of the active war should have been a handful of episodes tops. The Cardassians were a great species, but could we have seen someone else beside Ducat so much?
Once Next Gen went off the air, DS9 became the only game in town for stories about the Alpha Quad superpowers, and I always liked how the writers handled them. Everybody seemed to get much more screen time on DS9, and they were used far more effectively. Sean