If you like the core gameplay as it's in vanilla, yes. If you're looking for harder game and better balance, FWE is the one to look at. (or that's atleast my impression after playing a bit of FOOK2 and a lot of FWE).

However, not everyone wants a Harder game. Some like to play a game to relax. Like me.

And possibly everyone who likes FOOK 2.
I agree it's not as hard as FWE by any stretch of the imagination.
At least FWE/FOOK 2 doesn't turn Fallout 3 into a Bullet Hell shooter.