Apologies for resurrecting an old thread, but it may be of interest to some...
I've just got hold of an X-T2, and have started the migration process from Canon EF/EOS to the Fuji X line -- love the small form factor, and control layout.
Only problem is the cost (and sometimes the reported quality) of Fuji X glass. Selling off my existing Canon EF glass, and replacing with Fuji native glass, would take more money than I wish to part with.
Then I came across a YouTube video about the Fringer EF-FX Pro II:
Fringer EF-FX Pro II Review
I had no idea such devices existed...and it seemed too good to be true. But further research confirmed that the Fringer "just works", just as the YouTube vlogger above reported.
However, at £349 new, it's not a cheap purchase. Luckily, one did come up on eBay recently, and I was able to get one of these to try out at a price I could afford.
After experimenting with it, I'm happy to report that it works very well, on the whole. With my EF 24-70 f4 L, performance is truly excellent. AF just works, incl. Eye tracking, and so does OIS. My EF 70-200 f4 L does not do quite so well with AF, with occasional misses (really only an issue in low light). Both lenses are fully supported by the Fringer firmware (now updated to V1.90).
My EF 50mm f2.5 macro is not in the supported list, and though it works reasonably well, it is noticably less good with AF via the Fringer to my X-T2. Happily, I use this lens mainly in manual focus mode, and there it functions perfectly.
Looking at images taken with all three lenses, I'm impressed with the results.
I also have a EF 28-70mm f2.8 L, again not supported by the Fringer, and performance here is not good as far as AF is concerned. MF is fine, of course. However, this lens has been superceded in my bag by the 24-70mm f4 L, so this is not a big problem for me.
All in all, the Fringer EF-FX Pro II adapter has saved me a great deal of money. It does work--and having all the EXIF data come through in the RAW files is very helpful back at the computer.
No doubt in time I'll acquire native glass, but for now, my kit bag now holds my X-T2, the Fringer, and 3 Canon EF lenses, along with my existing Lee filters for landscape work. I'll need to add something at the wide end at some point soon, but basically, I'm otherwise sorted. I'll have to get my 28-70 and 5Dii sold, and then perhaps buy a Fuji wide...which to get?