rodsprint,
the MAX pressures in the manual are just that. If you ride solo and are of an average weight and do not carry luggage and inflate to the max pressures most tyres at that pressure will not work the way they have been designed to, will not reach correct temperature, and grip and ride will be compromised
Most tyres will not perform at their best at that MAX pressure without the accompanying load. Many riders here have proven this over and over again on this site.
This has been hashed over many times here and the vast majority of riders have agreed with me on this.
Conti Road Attacks seem to be the odd man out in the sense that they run better at higher pressures than most other brands available.
Different tyres work better at different pressures they are not all constructed the same way or from the same materials.
Doublenikkel,
I am unsure what bike you are refering to when you say you used to run 28 front and 32 rear on Michelin sports tyres but unless you are on a race track that is too low for a Sprint.
I am running on Michelin Pilot Race mediums at the moment and run 33 front 36 rear, at these pressures in my warm climate the tyres work very well, plenty of pics of different types of tyres in my albums in clicky below.
DaveM