I guess I fall into the school of thought that where a little's good, more's better.
I'm pumping my Continental Top Touring 700X35 tires to 100 lbs psi. It says the max is 70 lbs psi. I pump my Nokia studded tires to about 90 even though it says 65. I don't use the Nokias loaded, though.
If not, my tires look too flat when the bike is fully loaded. I've never had a problem doing this so far, and have been through several of these tires. should I be worried? I'm thinking of trying Schwalbes also.
Sheldon Brown seems to pooh pooh that max pressure rating.