I'm confused here after doing several dozen transfers in FRA I find it one of the easiest and best places in EU to transfer. I swore off LHR long ago, it may very well be better now with *A all in one terminal I haven't tried it since that change. The now gone LAX-FRA was better than the SFO flights as I believe the SFO flights typically landed over in B or C and the LAX flight was typically A53 or something like that but even the walk over to the EU gates isn't that bad. Even my first time through FRA I don't recall getting lost or it being that difficult to follow the signs to where I needed to go, also I don't think I've ever had more than 1 or 2 people in line in-front of me for passport control.