Mirrorless cameras are GREAT for when you want quality without the bulk. I carry my EOS M around with me more than anything now.. I have all but retired my ancient 20D LOL. I will be getting a 6d or 7dmk2 or 70d when the hobby pot is full again.. but ok, back on topic.
Mirrorless cameras are awesome! They take DSLR quality level of photos in a smaller package. My EOS M has the same sensor as the t5i for example. Most can also use adapters to run full sized lenses if need be.
I carry a 22 f2 and the 18-55 f3.5-5.6, and mostly leave the 18-55 on it, as it does a great job as an all-a-round lens. I will be getting the 11-22 at some point along with the 55-200.
There is the M2 and M3, and they are not for sale in the US, but the original M can be had for 300-350. It is slower focusing than other brands in some regards, but the photo quality is great, and the touch screen UI is really nice! Others will be along to give you their favorites too, but so far I love my EOS M. My ONLY complaint is no built in flash.
Here it is with the EF lens adapter and an EF 20mm on it and the 580ex flash.. just being silly.
low light