Mirrorless

[neuroanatomist]

Whilst the M has is big faults and annoyances, the great plus is being able to slap any EF lens on it with the adaptor and it works

Although... I look at the Fuji range of amazing fast lenses and kick myself sometimes ;-)

At this point, it depends on your intent. If you want a mirrorless *system*, Canon isn't the best choice (at least for now - that will change if they continue to develop the line, but they're really just entering the market).

But, if you want a small camera for occasional use that *integrates* with the system you currently use (assuming that's Canon), then the EOS M is a great choice. A large sensor in a small body (very compact with the 22/2 pancake), functions as a very portable backup body, great for occasional use.