Cameralabs is working on a full review of the Canon EOS M (using a final production model), and while it is a work in progress they are sharing new bits when added to the review. A long and detailed introduction and first impressions section delivers all the information you need about Canon’s supersmall MILC (Mirrorless Interchangable Lens Camera).
The Canon EOS M has some weak points, as every camera, and among the positive sides the following are pointed out:
First is obviously having compatibility (with some limitations) to the entire EF lens catalogue which makes it extremely tempting to existing Canon DSLR owners. Second is having a decent sized APS-C sensor with performance that’s identical to an existing EOS DSLR. Third [...] is also sharing the movie capabilities of EOS DSLRs including a decent array of frame rates, full manual exposure control, audio level adjustment and the chance to connect an external microphone. Fourth is the standard hotshoe, which can accommodate any of the Canon Speedlites, and fifth is the decent touch-screen interface which includes pinch and swiping gestures. As for the hybrid AF system, this could become a big plus point or a negative depending on its performance in practice.
They are right when they refer to the fact that for the time being there is no real review of the EOS M’s autofocus performance in practice. However, the AF of the EOS M for sure isn’t its strongest point.
There are videos for you to check, EOS M sample images with various ISO settings, picture crops to check the sensor noise and covering the available ISO range. The Canon EOS M sports the same sensor and processing system as the Rebel T4i/EOS 650D, so no big surprises here.