25mm tyres

i run a 23 front and 28 rear. best of both worlds :)

Randonneurs are not really 28mm.

What????

Counter intuitive, but he's right. A really hard tyre will get more punctures than a reasonnably inflated one.

I cant think of anything worse than running my tyres at 80psi.
I can think of a few.

London roads being what they are, I'd say get a few more mm, you'll care less about potholes and won't be any slower.