Just a few thoughts on this. Firstly, the surface you're riding on will determine the optimum tyre type. A long time ago, when roads were maintained and not continually cut up by the volume of traffic they carry now, we had wonderful smooth tarmac. In the 1980s I had 19mm tyres for time trialling, with 120psi in them. On today's roads a tyre set up like that would be almost unrideable.

Secondly, the bike construction has a part to play. I ride 23mm tyres on steel framed bikes, but find that I need 25mm tyres on aluminium framed bikes to get the same balance of comfort and speed.

Third factor is the construction of the tyre - a good quality 28mm tyre is likely to be lighter, roll faster, and be more comfortable to ride than a cheap 23mm. (The exception to this is a Gatorskin tyre which is neither cheap nor nice to ride on).

​​​​​​If you've not read Laurent Fignon's autobiography incidentally itsi well worth reading - there's a passage in it detailing how wider tyres were initially not wanted by the pro's on his team until they were tried and proved to be faster.