Received my one of the 4800U equipped Lenovo's just a couple of days ago. Admittedly heavily discounted, but what AMD have achieved here for the cost (consider that Lenovo could even offer this for sub £500 with discount), and the power envelope is staggering. The 4800U in standard 15W balanced mode, NOT higher TDP performance mode, was for example EASILY beating my friend's Desktop 8700 based Mac in both single and multithreaded performance in Cinebench. Considering that was top dog around a year ago, and is now being handily beaten by a 15W mobile part, in single core also...
This was for my family, perfect all rounder little machine, and the 8CU Vega was surprisingly pokey. OK its not a powerhouse and intensive stuff can bring it to its knees, but it's actually faster than the 7750 GDDR5 model I had in my HTPC up until last year, and is able to run things like Doom Eternal around the 60FPS mark at 1080p, albeit with dynamic resolution scaling often dropping to about half that. With that in mind I'm sure it'll run anything at LEAST 720P 30FPS+, and a lot of stuff at 1080P.
Impressive for integrated graphics.