I bought my steel framed, full-sized, "Wonderfinish" 9x19 Witness a good many years ago, well before the "real" CZ 75's could be imported. Turns out to have been perhaps the best deal I ever got for the money I spent.
Fast approaching the 5-figures in rd. count, all it's ever needed has been two routine spring replacements. Nothing has broken nor worn-out. The sights came OTB perfectly regulated for my eyes and style of shooting with standard pressure 115 gr. loads at 25 M. Accuracy with its preferred ammo remains better than I can generally hold for on a given day and functional reliability with many different types of both ball and JHP ammo has been exceptional.
The "Wonderfinish" has proven to be extremely durable, showing only minor polishing wear on the slide rails and other contact surfaces.
You're likely to get a lot of negative feedback concerning EAA's rep for poor CS. How justified that may be, I can't really say as I've never had any reason to contact them.
I have no personal experience with the newer polymer-frame models, and can't comment on how well that caliber-swapping feature actually works in practice. AFAIK, the CZ "Cadet" .22 RF conversions do not fit EAA pistols of any vintage and I'm not aware of any being produced specifically for the Tanfoglio pistols.