^ I guess you either buy the quick-fix or not.
I found that, after 1:52 of Borg invulnerability, it came out of nowhere. I wouldn't call it a reset button, but I would say it smelled like someone got painted into a corner, and did a little hokey three-card monte to wrap it up.
(How did the Borg figure in "The Wounded"? Are you thinking of some other episode?)
Ultimately, if you're going to introduce a huge, indomitable enemy, you can't maintain your "everyone back to where they started" show format. If you're dedicated to your status quo, then you need to abandon the idea that you can have world-shaking threats on the show. Or introduce their Achilles heel earlier.
This overstates my case - BOBW II wasn't awful, but it didn't live up to the promise of BOBW I.