I would rather have the pat-down search. At least there's no chance of having a permanent copy of what my body looks like that way.
I don't trust the Govt., and nobody should make me feel like I have to. I'd rather be in a distrustful frame of mind, than blindingly let the Govt. eat away at my privacy without me realising what little is left until its too late.
The 'option' of go on a plane having been scanned, or not go on at all, is not a real option. So as long as I can choose whether to be scanned or not, I'll be happy enough.