I tend to shop at the cheap end So I’ve got a “Vectoix” (34t) and an OO “Ringmaster” (30t) the main thing so far as I can tell with the cheap ones will be weight, the number of machining ops to create the tooth profiles gets offset by fewer machining ops to lighten the things, hence they are cheap, but relatively heavy.
The main bit of value that the pricier brands add will be that reduction in weight, which is more time spent on the mill, SS may be the exception here; they’ve invested in in-house manufacture and do the direct sales things so they can do more of the intricate machining to lose weight, and offset those cost in other ways…
The materials are probably like for like across most of them, (I doubt any of them will be giving you their mill certs to leaf through though) I don’t know if RF, Works or Hope are doing any Hard anodizing or coatings to improve wear but I imagine finish will be just a little nicer and smoother on the pricier brands, I know the contact faces on the cheaper ones go through the anodizing within a couple of rides, whether or not they wear better after that is only really going to be answered by people using them longer term…