i just got the r7000 and the performance on 2.4 and 5 is no better than the ac68u.
i'm on netgear firmware V1.0.0.96_1.0.15 so i need to update, but i'm getting equal speeds from both routers right now, neither what i expected to get when i moved from my e3000 running tomato... which i now regret greatly that i sold.
gonna run this r7000 for the next few days, but if i dont see an improvement i'm gonna just keep the ac68u.
oh and btw, the r7000 is as large as everyone is saying it is. things about 40% larger than the the ac68u.
edit: yeh i'm pretty much getting the same speeds and signal quality with both routers. the ac68u has a better 2.4ghz signal though, especially after the new firmware .306