It's a split between them in different ways but in production very different.
I'm only intrested in gaming myself, see on toms hardware they had a review up but between the 5800x vs 5800x3d even in 1440p their was a noticable difference some larger than others but generally 5% overall.
I feel the key thing is the UK price, it'll be the swansong for my system so a 5700x vs 5800x3d is "maybe" 10% at 1440p but if the gap is too large in price it's harder to justify, i could see myself getting it at say £350 but much more than that i really not sure.
My main intrest in the 5800x3d is it's performance in RSR as i'd be upscaling from 1080p in that case this chip might have a little magic in that aspect, but still only in certain games but it's something i'm intrested in knowing about as a deciding factor.
I said a while ago and still feel this this chip is a test bed of things to come and i doubt they will be as mass produced as other chips, saying that it could turn out as the best chip the AM4 platform will get least in terms of gaming it's just the price that will either be a turn on or run away like hell LUL