I use a Profoto softlight reflector, and I also have a cheap-as-chips one I bought off Ebay for 70 quid. Both 22 inch.
Both are white. The Profoto was bought like that, the other I sprayed with standard white spray paint.
In either case, I absolutely cannot tell which one is which when the light is fired. There is no discernable difference that I can tell.
As far as beauty dishes go, you should just buy the cheapest, because it doesn't seem to make any difference at all.