I have the double-layer Vittoria Randonneurs, which are supposed to be more flat resistant than the average bear. Someone on TE recommended them to me a couple years ago, and I have them on 2 of my road bikes. So far, so good! I have no complaints and they don't seem unusually heavy to me. (I ride on broken glass and pot holes and other urban hazards. No goathead thorns or other exciting things like that!)
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson