I agree w/ other posts: basically where are your flight patterns? BD is, of course, very limited compared to LH and UA. I have flown BD several times recently and in short haul I did not like them any more/less than LH. if you travel lots to the States, then UA would be the way I'd recommend. You have to get the UA status, but once you do I think they pay extra attention to foreign members who make 1K or even 1P. While 1K's might be a dime a dozen at ORD or IAD, if FRA is your home airport, you are part of a much smaller pool of individuals and would have a chance to strike up personal relationships with ground staff. And I think everyone on all of these boards will agree, there is no substitute with having an "angel" watching out for you inthe program you fly with most often. (BTW--"angel": an individual airline staff person you get to know personally who is willing to bend the rules, offer UG's, and help take care of you. Often rewarded with little gifts from grateful travelers.)