Normal mode raids I always PUG. They are a lot more fun that way.

I haven't done a whole lot of savage raids, but the ones I have run were definitely with peeps I know, picking up maybe 2-3 through PF to fill the gaps. I've never been caught up enough to run relevant raids though. It is something I will consider if I ever get there, but the same conditions apply: NM=PUG; SM=Static.