I had some Ultra Sports for a while, they are now on someone else's bike. I've had no issues with them and even though they have poor reviews, unless there is some bizarre freak accident, it all depends on where you ride. If you're riding Conti Ultra Sports on normal roads that is generally free of most debris, they will last you as long as any other tire of the same price.

As for Thickslicks, I've seen many people with them (including people on this forum), they are for the most part fine and a pretty good deal, I think.