FlyerTalk Evangelist
Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: BA Silver, TK E+, AA PP, Hyatt Globalist, Marriott LT Plat, Hilton Diamond
Posts: 13,043
M&M is not a particularly good choice, unless you specifically want to travel a lot on LH metal and use specific lounges in Germany.
I would status match your BA Gold to Turkish Miles & Smiles. There's a thread on the TK board.
But 25k miles every second year keeps your *A Gold for another two years.
Aegean is also fairly reasonable for status, although you need some Aegean metal flights.