I usually use the Trojan Supra--they are polyurethane---simply because I seem to see them around more often.

However, my problem with the polyurethane ones is they only come in one size. I've definitely had breakage problems before. This makes me very, very nervous with those condoms, and I have a hard time relaxing during sex while using them because of the entirely justified fear that they will break.

Have you personally used the polyisoprene condoms? Have you used the polyurethane condoms? What are the pros/cons (in your experience) of the polyisoprene ones vs polyurethane?