I think that The Best of Both Worlds Part II was the better part of that episode. Part I really didn't have all that much except as a setup to Part II.
I disagree somewhat. Both parts together are top notch television but I felt the climax to Part 2 was slightly disappointing whereas that cliffhanger in Part 1 has never been matched in my opinion. The reason I only somewhat disagree is because there's a hell of a lot of great stuff in Part 2
I'd agree that Part 1 is superior. It's got more emotional meat to it, and a greater sense of impending dread. Part 2 isn't quite able to make everything stick together. Some of that's by plot needs: Picard's thoughts about the eve before battle, for example, cry out for resolution that can't be had in Part 2. The Shelly-Riker rivalry is great stuff in Part 1, but it's neutralized by the demands of Part 2. And the climax of Part 2 has that bizarre dull stretch, between the Borg going to sleep and the cube exploding. I know they were trying to go for suspenseful and mysterious but it feels like they somehow found themselves two minutes short and filled the gap with nothing.