8 beams is still a bad idea, and always has been. Hulls just go down too slowly without torpedoes, and firing 8 beams at once drains enough power that I'm not sure it's worthwhile.
Now 6 or 7 beams with FAW is pretty powerful. But if your talking about the Excelsior, you're kind of limited to FAW 2. You can go with FAW 3, but then you can't get APO, so you're kind of depending on your opponent not using tractor beams (especially with the Borg sets, it's a virtual guarantee that half the enemies you face will have tractor beams). FAW 1 or 2 is pretty easy to get without really giving anything up, but that's mostly because LT and Ensign tactical slots just aren't that valuable; FAW 3 seems to be the one people are complaining about, but if you're not on an escort you can't slot it without giving up some other major ability.
Hehe Power drain not a problem, there is skills for that.
And the use of FAW 3 is just to make ppl like you aware of the OPness, so you go and complain in forums so cryptic will make it back to normal