So i get the magic booster ultra for 4.6K, everything looks great but unfortunatelly i cannot focus to infinity with canon 16-35 f2.8 L II on focal lengths 16-20mm. Tomorrow i will send it back, Luca told me that he will be able to fix that. More than 20mm is okay and 16 is ok with aperture around f10. I tested canon 70-200 f2.8 L IS II and canon 100 L IS macro - both are ok.
It is a remarkable thing for 4.6k! Really, i am astonished how good the image is! What is interesting - with the magic booster installed i tried sigma 8-16 - of course it gave a very strong vignette as it is apsc lens - but for 2K 120fps crop it is great - i will be able to get ultra wide angles for 2k raw slomo!
Installing is not as bad as i thought after watching some reviews, just couple of minutes in more or less clean environment - i think i will be able to mount and remove this before shooting day... With adapter installed sensor also is much better secured - and it is much easier to clean the adapter with a cloth when something get inside during lens change versus cleaning the glass filter which is very deep inside.
I have made only a quick tests with flowers and stuff but i know that when i get my magic booster back i will use it a lot! I used 16-35 f2.8 L II (16mm only with close focus) and 70-200 f2.8 L IS II.