I have an '01 Tundra Access Cab (i.e. short bed) with the factory tonneau cover. I have been very pleased with it. It uses an aluminum frame with a "C" clamp, similar to that used on canopies, to hold it to the bed of the truck. There are 6 clamps total, three on each side. There are three "ribs" that bow up to help shed water. There is a gasket that rides on top of the top lip of the bed and provides for reasonable "water proofing", although nothing is perfect. You are still succeptible to condensation if you live in such a climate (I do).
It has performed well for two years now, with very good wear. No special cleaning required.
What do I like best? Great fit and very functional. What do I like least? The cost of replacing is quite high (unless you have a line, which sounds like you might), taking the cover off and putting back on is time consuming, and requires that you lie on your back to tighten up the clamps. If you have the factory bed liner, this becomes quite uncomfortable. There is an option to roll the cover back, but it is very labor intensive, and is likely easiest to take completely off.
Do I regret buying it? No, not at all, and would do so again given the good price I got (bought my truck via an employee purchase program, so the price was very favorable).