I think the better card will be the 3080 20gb if and when it comes out, it's never good to be an early adopter, always better to wait let the dust settle, i mean the 3090 will be stronger it's a given maybe 20% like kaap said idk really but it's a lot of money for a card always better to know for sure.
I mean even if i had the money it's way out of my league, but even the 3070 while I could jump for it, after nvidia's marketing and seeing how that turned out with the 3080 not so sure, but also i can take into account early drivers cards always improve so that's another thing.
I'm not saying the 3080 is in any way bad, but it's not twice the performance of the 2080 like nvidia said in the launch stream, otherwise it's a good card.
I don't really have a choice I need a card but i don't want to decide until i've seen them all.