There needs to be viable alternatives
Like tractor, gravity turrets, mines, fortresses, sniper/spider?
Yes, FFs in their current form work, but work rather badly.
I disagree.
Chris specifically mentioned in the AI War II design document that (paraphrasing) the game should be about grand strategy, not about looking away from your base for 10 seconds, coming back and your most important structures (under a forcefield) are gone.
To me, that was one of the main reasons forcefields were being examined in the first place, but also because of the technical and engine trouble they caused.
So yes, I think it's safe to say that if Forcefields were working well, we wouldn't be having this discussion in the first place.
Which isn't to be hostile, because each person is entitled to their own opinion. But if we want this game to reach a wider audience than it does, I think "instagib" mechanics like that need to go. The first time a reviewer spends 12 hours painstakingly creating a space empire and then loses to a few Raid Starships in about 30 seconds, it's probably going to crush their high opinion of the game. I wouldn't blame them for that either.