my latest Leica purchase is the Viewfinder Magnifier M 1.4x. I hesitated a bit buying it but finally am very happy to have it now. Its a bit pricy – comes in for about € 250,–. Also I have not been sure if you see the 50mm frame lines, but after using it for some time I can tell you see them if you push your eye close enough to the viewfinder.
From the point of usability it is a thumbs up from my side. The rangefinder patch is much better to see and focusing speeded up.
If you can’t decide to get the 1.25x or 1.4x for a 50mm in my opinion get the 1.4x.
You get along with the magnifier a little leather case for storage as well a little chain.
Just to highlight: bought @ Digitalstore Vienna – my trusty Leica dealer!
Here some kind of unboxing pictures I took with my new X-Pro1 and the 35mm 1.4. (Click to enlarge)