I can't comment specifically on the security for an AA flight, but I traveled on LH last week from FRA to BOS, and security was rather unpleasant.
All the US bound flights were grouped together at the end of the concourse, and there was an additional screening point for all US bound pax. There were a lot of US flights leaving around the same time, so I'd say there were probably about 80 people waiting in the 5 lines. The J/F line was a little better, with about 15 people waiting for 2 lines.
The delays were a result of wanding/groping every single passenger - including all infants and children. Children were not allowed to hold a parent's hand, resulting in quite a few objections.
Security screeners were opening most carry on bags, though hardly seemed to be looking inside on most occassions. As ever, the level of scrutiny was based on which line you were in - I was allowed a small bottle of lotion (which the screener even picked up, looked at, and placed back in), but I also got grilled on my little digital camera and why I had a second battery.
Not sure if things have mellowed out a bit over the last week, but I'd allow a little extra time!