It's nice to have. I can usually keep the planes and choppers in the air, but it's still good for newbies.
I absolutely disagree with people who say BF needs Saint's Row style helicopter controls. I haven't played SR, but Just Cause 2 used the same controls, and I really didn't like it. It doesn't feel like a helicopter at all. I don't need the realism of Take On Helicopters, where just taking off will take 10 minutes. But I do like to feel like a bit of a badass when I pilot these things, as opposed to the SR/JC model where I needn't even look at the screen to fly.
By the way, I never use the mouse for flying, I bind the arrow keys as alternative movement keys for choppers and planes. Works fine.
The one criticism I have is the use of unlocks for basic functionality of the planes and choppers. Planetside 2 did this too, the fighters near-useless without the very expensive rocket pods. And in BF3, you started of with just your onboard cannon on planes, and you needed to somehow score points with just that to unlock the weapons you need (at least the AA missiles unlocked early in BF3). It's one thing that new players lose because they don't know how to fly yet, but you shouldn't compound the problem by witholding the equipment they need to have a fighting chance.