Can confirm. I built my bike with R8000 (R8020 actually). The GF had a bike that had 5800 and it was trash, could be it was worn and not a bad group set but either way is wasn't working well no matter what language I sweared at it in. I got her a R7000 groupset for a Christmas present and I was impressed with it - comparing it to my Ultegra kit. I suspect the bulk of the differences are on the scale, and how much does that really matter?