"Descent" is the weakest of TNG's season-ending/beginning two-parters, and appropriately enough it kicks off a very uneven 7th season.
There are a mishmash of ideas here, all of which are pretty underdeveloped. Why should we care about Lore now that the novelty of "evil Data" has worn off? Why do we care about individualistic evil Borg instead of communalistic evil Borg? Why is Hugh so annoying?
This episode does have a few redeeming moments. Overall, despite a ton of talking, it has its share of excitement. It's kind of fun to see Crusher commanding the Enterprise - she exudes authority, unlike Troi in "Disaster", though I'm not sure we really needed to endure the "young shy ensign makes good" cliche. And the ending between Geordi and Data is a nice, tender note to wrap things.
But in the end - nothing ventured, nothing gained, and nothing worth remembering.