Advanced legacy lens user: What to choose Olympus OM-D E-M5 or Sony NEX-6?

Yurus, this can come down to personal preference with the ergonomics. I use alternative lenses all the time and have for a long time. I have the Nex5n and the OM-D along with ten or more adapters. Many will point out focus peaking. I never got along with it for legacy lenses. I sometimes put the EF400mm f5.6 on the OM-D for surf pictures. With the OM-D this works with the tripod bracket which is on the lens. I have never achieved anything with it on the Nex 5n. Ergonomics  are so uncomfortable. I am aware the Nex 6 is not the 5n but they do share a similarity in ergonomics. Using lenses such as the induster, jupiter 8, OM mount , CY Z 50mm T*, I still find the ergonomics on the Nex design to be somewhat clumsy and uncomfortable, against a more traditional designed camera like the OM-D.

This from personal experience has been my conclusion and now rarely using the lenses on the Nex. Hope this helps, really what I am saying is that I would try and look at the ergonomics as an issue as well and even maybe as a priority in many ways, then go from there, as both systems are very capable in producing excellent images.