Not mind larger body & heavier lens, then DSLR of course. For DSLNR, it seems NEX series is better concerning response. EOS M is slow in focusing (I know before I have one) although the picture quality is good. I am a canon user, however if you have no preference you may consider Sony (entry level) DSLR with Kit lens and speedlite as it cost approx the same as the EOS 650 body.
Get a NEX if DSLR is not a must. Since is is a lot smaller and lighter, easy to handle as well. I am a Canon DSLR user and have a EOS-M, for me the draw back of EOS-M is no speedlite in the body and have to take a speedlite which increase the weight and less convenience.