I used the Visio flex 2 on the M11.  It was great, with the EV1 being much better experience...focus helpers are the magnification and focus peaking.  Collectively they work great together.  I do think the EV1 gives a clearer picture and better focus experience.

It's pretty amazing.  Very easy to focus and definitely seems accurate.  For me, with my eyesight, it is definitely faster than my M11.