I couldn't care less how big their ground is, fact is they will fill it every week with day trippers carrying their Ipads. We need to be realistic, 60k is about the maximum we should go, there's nothing worse than seeing a shitload of empty seats on a matchday, the Emptyhad is a prime example of that, City are the Champions elect and yet can't fill their own stadium.
I reckon there woul dbe lots of empty seats quite often at 60k myself.
That, in and of itself, isn't the end of the world as long as you have a smart ticketing system.
But i think 55k is the sweet spot personally