Road Cycling - Tire change on Cyclocross

I am about to replace my cyclocross nobs(Hutchinson 30s) with a street fit tire on my Cannondale Cyclocross. How much of a difference will I see going to a street vs. nobbie. The ride now is not as smooth as it probably could be. Is there a great difference between a 30 and a 28 on a 700 wheel? I am concerned with smooth ride (C'dale is pretty stiff, yet nimble), and also the possibility of many flat tires; I hate changing tires. What model would you suggest? Don't want to go too narrow. Any suggestions would be welcomed.

Urbanmonk :D

Well you could get a smoother cyclocross tire like a Ritchey Speedmax or a normal size road tire but with build in flat protection.Specialized has lots of those kind of tires.

The Rivendell Roly Poly is a really nice tire.
The same thing with kevlar is called the Ruffy Tuffy. At 27c with a wide profile, it's a nice compromise between this 'n that.

I think you'll notuce a big difference with the road tires on. A CX bike makes an excellent road bike really. Very comfortable for long rides. I put Continental 25's on my CX/Tourer for the road. Tire pressure has a lot to do with it. My tires suggest 120psi and I fill them to 100 for a more cushy ride. 28's will even be cushier.

For flat protection, go with the Specialized Armadillo. Should be available in a suitable size.

Do the Armadillos come in a 28? I want to get as close to the 30s I have on right now. Also, would you suggest Mr. Tuffies for the Armadillos and punture-proof prestas; and goop in the tubes. You don't understand how much I hate flat tires; it borders on something psychotic. I know, I need help; I'm sure there is a support group out there somewhere.

P.S.: Is there a big difference between the Armadillos and Continentals?

Thanks for all the tips, all.

Urbanmonk