Thanks for all the comments.

My original question was about Continentals. I ended up ordering a pair of GP-4000S II from Competitive Cyclist as they have a good price right now. When I spoke to them they said that their experience was that they have better longetivity than the Michelins, since the Michelins tend to suffer from dry rot, which of course has been my experience.

The mention of Vittoria reminded me that I have some Vittoria Open Tubulars in my closet, so I may put them on while I'm waiting for the Competitive Cyclist order to come in. I think they're not heavy duty puncture proof, but I might as well try them out.