I ditched the DSLR (Canon 5DIII) and went mirrorless and loved it for a while - I went to the OMD E-M1, a brilliant camera and system and Olympus really do support their kit with serval revisions firmware improvements - new features too, not just fixes for obscure lens combinations - and with another update due out next month that will again improve it despite it being old(ish) but... and there was a but for me - my style such as it is involves that pop from full frame, now don't get me wrong if you got the 75mm 1.8 you get close, but it wasn't quite enough for me so I moved back to DSLR (Nikon this time).
Nothing against MFT or mirrorless, the advantages of size and the EVF is incredible, I just missed the full frame look - and it took me a fair while to figure out why I was unhappy with my shots, so it was just not for me...
Just a bit of a heads up in case, certainly not meant to put you off, as I said MFT is great and some of the lenses really do bring out an incredible amount of detail.