Wife went from a 3080 to a Nitro 7900XT. She plays at Ultrawide 3840x1600, and everything runs better than the 3080 which was really beginning to struggle a bit at times.
She gets better performance at UW with the 7900XT, than I do at QHD with a 3080...so yeah definately more powerful, and no worries at all about VRAM anymore, as the card has 20GB compared to the 10GB of the 3080, so should avoid any memory relating hitching at all if the framebuffer is exceeded.
She's had very few issues too, it just works. Our 3080s consume roughly 350W also, so very little power consumption difference.
If the 8900XTX or whatever its called comes out and genuinely is a 7900XTX, marginally faster, better raytracing, and costing £500, I'd be very tempted, as we all know Nvidia's Blackwell is not going to come cheap, even if it is decently faster than the 4 series.