is there any marked difference between all of the different 6600s? my rx480 is getting more and more angry at me and I'm not sure how much longer I can wait out the current pricing nonsense.
I don't think so.
I like the MSI models because they have a 3 year warranty that is transferrable, and you don't even need a receipt but in that case they use the built on date associated with the serial number vs the sold on date. I've have good luck with MSI cards in the past... that's about it. When I posted originally it was just the only one available.
I'd say the actual performance is the same, so go for the warranty, aesthetics or price to guide you
Good news is that this is a real step up from your RX480 and is likely more efficient too.
The big splurge, imo, would be to get the XT model for $70-$120 more. It is measurably faster but is in the same class of card. As you appear to be someone who spent more on a 480 when the 470 existed, I merely mention it. It's pretty much the same dynamic.