Good friend of mine is based at BHX, and loves it. She has flown for charters in the past, but enjoys KLM much more. Money is ok, and promotion is fairly fast, certainly if you have experience. Your rosters are fairly busy, but I think you get some decent day/nightstops in AMS. As for the merger, I have no idea I'm afraid. All this is just what she says, obviously other crew/bases may have totally different thoughts.
MR XxX