I have been pretty discouraged by wheel coatings in general. I just think the wheels take a beating during their lives - brake dust, road grime, curbs, sand, ice, salt, etc.
Even when applying a bonafide coating to wheels, I can`t seem to get more than 6m out of it - I mean no where close to the life and cosmetic appearance of coatings on paint. I`ve had my coatings on paint last 1y to 18m (only because I`m correcting the paint again), but not on wheels.
Haven`t tried Sonax at all. I remain a fan of HydrO2 and Wet Coat on wheels. Only get about 6-8 weeks out of them (at best), but they are very easy to apply and reapply. Almost effortless.