And just think: The borg set's already been nerfed pretty hard. There's still a lot of people who say it's been nerfed to worthlessness (just a few days ago there was a thread where the consensus was the Breen set is better now), but it's all noise. It's still pretty hard to justify dropping the 2 and 3 piece bonuses.
The shields for the Borg set are fairly... unimpressive.
I love the Borg Retro Set Shields, my shields rarely fall and if they do there back in a few seconds.
What a lot well more then a lot a ton of people don't do with their shields is keep them equalized and if you are running with regenerative shields (Which the Borg Retro Shields are) keeping your shields equalized is very important.
Regenerative are very good if you keep them equalizing, if you can't keep them doing this then yes regenerative shields are not that good. That is why I bound Equalize Shields and Fire all weapons to my spacebar so that every time I fire my weapons I am also equalizing my shields. Even if you have all you weapons on auto-fire, binding equalize shields to some key you can hit over and over again with no problem will increase your survivability and love for regenerative shields.
When I first got the Borg Retro Shields I never liked them, they seemed to fall very quickly, until I tried keeping them equalized. Now they are my favorite shields and the Borg Retro Set is still the best set in STO in my eyes.