My take on the EOS M

Yes, as everyone says, the auto focus isn't great but the camera's silly cheap at £229 with VAT (and 18-55mm IS STM lens). Additionally, I can use all of my EOS and ancient FD lenses, the former with full automation.

It will never replace my DSLR but, so far, I'm amazed at the quality of images. Unfortunately, once I got used to the touch screen, picking up the 7D feels like yesteryear.

Consequently, it's usually in my pocket and I use it more often than I thought I might. It's great for video too especially with the EF-S 10-22mm.

Size comparison, EOS-M vs 7d with standard zoom lenses

Meike EF/EF-S adapter

This adapter allows Canon EF and EF-S lens to be mounted on the EOS M. All the electronic features of the lens works, autofocus, IS, aperture control etc just as though the lens was on your Canon DSLR. Canon make such an adapter but it's expensive so, since I will only ocassionally be using an adapter, I chose one of the copies available from eBay. I went for the Meike and after several years I'm still very pleased with it and can highly recommend Meike.

FD/FL Lens to EF M adapter

One advantage, should you have once been a canon FD user, is that the EOS M can accommodate all your old FD lenses with a simple and cheap adapter. The lenses will still focus to infinity but, of course, you'll have to focus manually.

My findings: all this shows is how bad my old FD lenses actually are compared to modern-day EF lenses, with the exception of my FD 500mm f4.5L. Consequently, I only use this adapter with the 500mm.