I ordered the part after 'Rene's and "# Bazi2012's review. The copy delivered corresponds to the mechanical properties of Rene's description, with the diopter adjustment I had no problem (I had not even adjusted for a perfectly sharp image). Calibration and mounting on Kameragehaeuse per cylinder screw with Allen I find practical and stable. touch screen functions are of course with attached viewfinder can not be used ... but a closer look is thanks to the small red Raendelschrauebe removed in a few seconds and plugged again.
The Wallimex-viewfinder works for me on all cameras from the above list. Composition is the lupenvergroesserten screen at least for me very simple and intuitive - better than with some EVFs, the Panasonic GX1 except times. I have in recent days on events some hundred recordings with the NEX-5R made with attached viewfinder and manually focused lens (Summicron 50mm f / 2 with NEX adapter) made, thanks to the increase in the viewfinder manual focusing is fast and accurate - almost all the shots were perfectly sharp. The focusing works for me with the viewfinder on the Nexen better and faster than with the EVF of the NEX-7 ... focused manually you're there with a little practice, significantly faster than the AF of Nexen ... Focus Peaking should be on, and the electronic magnifier for critical cases is griffguenstig on a function key, which enables very fast switching. Combining manual lens - NEX - Wallimex-viewfinder is still very easy, but quite long - the handling of the combination is different than a small DSLR, a for me a pleasant way.
Only downside is the air gap as described by "EH Stuttgart" between tube and LCD screen - although I previously had no real problems with stray light, you can see it in certain angles of incidence areas of sunlight / the lighting, how dirty a LCD screen on a can be camera (fingerprints, dust (; ->)) ...
This air gap for occurring by limited adjustment range and the relatively high price - it is, however, compared to retrofit EVFs guenstig - I was thinking about a star deduction, but think then but that must be five stars in the sum of all the properties.