Well like on VOY, for whatever reason, the Borg 'reset' in each major episode/film, where ANY weapon seems to work for the first few shots.
Yeah, I thought the sphere was pretty wimpy. Though it could be argued that it's purpose was to distract the E until the Borg were all on board.
I wonder how many drones actually transported over, and how many the sphere carried? I always suspected only a handful, into the Jeffries Tubes...