OP is in orange county - in which case timing/routing would be my deciding factor (and always is for this exact dilemma). If you're going to drive to a larger airport (LAX or SAN), then I would go for LH because you can take the non-stop to FRA/MUC which are timed better for sleeping (and longer as well) and avoids the extra connection to do the same for UA (E.g., LAX/SNA-SFO-FRA-XXX). If you're going to fly out of SNA, then I'd go off of times because either you'll have to connect in SFO/ORD (or others) anyway so you have much more options.