For whatever reason, the PlayStation half of my sig doesn't update anymore. It hasn't for months. If it did, you would see that I play PS3 games as well as Xbox 360 games quite often. Anyway, I have every 7th and 8th gen console connected to a 4K and I jump between generations, at least weekly. I'm never jarred by the jump. Aside from how slow last gen dashboards are, that is.
Don't get me wrong. I appreciate a good 4K image and a great frame rate. Good textures and lighting are also a plus. Last gen still looks good. Damn good.
Going from 7th gen to 6th? Huge jump. 6th gen to 5th? Huge jump. 5th gen to 4th? Incredible difference. 8th gen to 7th? It's alright.