The 'sissy' BORG from VOY had many weaknesses that the show brought up to defeat them, to name a few:
1) Inability to detect those that did not pose a threat to their vessel, or where irrelevant. Have the BORG never heard of internal sensors?
2) Species 8472 which kicked their butts in a few shows.
3) The internal DNA thing which made certain drones 'dream', never liked this one either, why couldn't the BORG just check for REM during this deep dream mode.
There are more, but I can't remember them all
Now the TNG borg were omnipotent, unstoppable, everlasting, nearly immortal. You hit them with everythin you got and they keep coming. Even Picard lost to them( he was assimilated), and the Trojan Virus-like plan was shelved, because it was unethical. It took the best and brightest long to figure out how to destroy ONE cube.
VOY took on countless cubes and won.
If you need an enemy to make your players run screaming pleading for mercy and redemption(like mine do), then use the BORG ala TNG. If you need an impressive, powerful vs phasers kind of enemy which will act without emotion then use the BORG ala VOY style.
I have only used the BORG once, half my PC's died or were assimilated, the only good side was that one managed to save a Cardassian vessel also stuck inside. The assimilated PC's later make cameo appearances as plot devices.
"The misery of being exploited by capitalists is nothing compared to the misery of not being exploited at all."
-Joan Robinson, economist