It is all up to personal preference. Performance wise there is not much difference anymore as autos are really quick and sometimes quicker than MT. AT traditionally used more fuel but the difference today is nothing. AT is more convenient, especially driving in the city but manuals are more fun (I think).
Traditionally in Sweden almost all cars come with MT as standard and AT is an extra option, the opposite from the US what I understand. Today AT is oftentimes favored driving in the cities but active BMW drivers mostly go for MT, at least if you're not looking at one of the cars with DCT (M).
I drive a MT 335i and love the manual but have driven the AT and it is fast and for the turbo 335 it holds boost under shifting. My GF would also would have preferred the AT.