My Marin Mill Valley came with Vittorias. One failed catastrophically riding home from the shop. The other died a few weeks later.

I've had better luck with Continental Gatorskins and Specialized Armadillos.

I'm going to try 70x28 Schwalbe Marathon Plus next to try something different. They're supposed to be better than the gators and 'dillos from what I'm told here.

It's hard for me to tell the difference but I did notice two flats in the last week, so I think I need new rubber. I blew my pay on a saddle, pedals, shorts, gloves, tubes, patch kits and a torx wrench, so i'm hoping to get two more weeks out of the Contis.