I wanted MAN when I joined at the end of Jan and was offered EMA or CDF. I took EMA, but got to MAN 3 weeks later before I got near an aircraft

. Its not always like this of course! It depends on many things (time of year, fleet, base expansion etc) but most people reckoned on 6 months, after all, they want you to be happy! Man will have 4 737's this summer I believe, which meant quite a few new guys went there. Its worth the hassle I think, there are always crew looking for house shares etc.
Hope this helps