FCross - I asked RL almost the exact same question a couple months ago. My experience was very similar during the break in. 1-2 rds out of every other mag would jamb or not eject. It stopped after around 160rds and the last 2 trips to the range, about 120rds and I haven't had a single FTF or FTE.
As far as the trigger goes, I actually like the one that came from DPMS. It's nice and smooth and with a good solid squeeze feels comfortable to me.
I've been shooting my friends pistol at the range the last few trips and I don't like his trigger at all. It's way to long a travel and too soft. It might just be a comfort thing.
Now I have installed RRA 2-Stage triggers in my other two AR's based on the reviews and advice of fellow members here. So far the information and advice from the experienced members here has been top shelf.