Well to the 3 that replied or anybody interested...
I got the RT-AC68U since for £20 more may as well get the dual core/1900 router but for other (physical) considerations too.
Firstly, unlike my 7800N the RT-AC66U has vents only on the bottom where the 7800N had vents on the top and all round too and the router would be sat on a carpet floor so not optical. Therefore I'd have had to have it stood up which isnt great since the ports would then be at the top so the AC68U makes more sense on that front. Plus the 68U has a button to turn off LEDs. I like this. (I've put inulation tape over the the openreach modem LEDs)
Anyways, set it up, disabled all the rubbish I don't want, enabled 5ghz only on my phone and went to the other end of the house where I often got poor speeds on the billion and ran a speedtest...
Yep if it maxes out my connection I'm happy with the performance.
I just hope the stability lives up to the claims on the box
"FAST Networking Solutions | F
AST - EA
SY - ST
ABLE...hmm guess I'll see.
Currently Plusnet "80/20" FTTC...Not overly impressed at the moment :|