Hm... I've been eyeing the 4070 for my personal rig, but wondering lately if I should just grab the 3070 while I can, because I worry about being able to get my hands on either once the former launches. If I wait for actual reviews of the 4070, it may be too late for me to get one in the near/mid future.
If this leak is accurate, and the improvement is "only" 25%, roughly matching a 3080, I'm leaning significantly more toward the 3070... The only thing I'd be sad to miss out on is improved RT performance, and possibly unannounced features. (Is it known if 40-series will support AV1 encoding? Will there be an updated version of Nvenc?)
The wattage numbers that have been leaked are actually a big deal to me. My room already gets unbearably hot within 30 minutes of gaming with a 2060. If a 4070 is double that? My next gaming session might be my last. : -P ... a 3070 won't produce too much more heat than my 2060, plus I've heard that 30-series are good undervolters (or at least the 3080 was if I remember right?)
/thinking out loud