I just watched Kai Wong's video on the EV1 and I don't really get it either:
In short: all the benefits of the Leica sensor and sensor stack with all the typical issues of an EVF. Lovely.
I know there are people in here who adore EVF and focus peaking, but Kai's issues with it in that video almost exactly match my experiences with it on all the Fuji bodies I've owned. It's too easily tricked; strong contrasty shapes (like printed type) can be incredibly hard to focus on with an EVF.
It'll be interesting to see if Leica add extra "focusing aids" via firmware upgrade down the line, but yeah, not for me, thanks.