Though I initially liked seeing the Duras sisters again, on subsequent viewings I felt they shouldn't have been used at all. Generations wasted them. I wish they had not used the Duras sisters and made them exclusive to DS9. I think their political machinations during the Federation-Klingon War and with the Dominion would've made for some interesting viewing.
I wish Generations had used the Ferengi instead, perhaps DaiMon Bok. To me it would've been a nice homage to TNG's first villains and I would've gotten to see a Ferengi Marauder on the big screen. I do think a Marauder is a more credible threat than an old Bird of Prey.