Mrs. J-H and I flew JFK-FRA-CPT last September on LH. Its a long layover in FRA, but we managed to show up at a wine festival outside FRA. You can take either LH or UA from IAD - but I would HIGHLY recommend flying LH F for the comfort, service and food...The upperdeck LH is EXCELLENT, though not as great as the nose section of UA F - but in terms of food and service, LH F is at least a few notches above UA F.