I have never compared Leica glass to Olympus glass. I do know that (especially since I shoot prints) a 92% viewifnder is bad enough for composition, let alone having another fairly large "blackout" area on the right side. The design is very amateurish, and I wonder why the vaunted Leica brand went with this?
As far as I can tell, the R4 is based upon the XD-11, and the XD-11 looks to have the same viewfinder (which is why I never opted for an XD-11). I opted for the Leica strictly for the glass, but I wonder exactly how much better the glass actually is. I have taken some beautiful shots with Canon, Nikon, Minolta, and Pentax glass. Certainly, these other brands are at least a better value.
Further, Leica's design and features on the R4 were way behind its Japanese competition. I compared the R4 to a number of Japanese bodies that debuted *prior* to the R4, and found the Japanese bodies to be more advanced.