I've done some thinking and taking a closer look at the toilet seat on my Dometic 310. The seat & lid & hinge is one-piece and not your regular unit that can be found at a Home Depot or wherever. What was bugging me the most was how difficult it was to clean because of so many nooks and crannies. It took more time than I was happy to spend on the task, and I never felt I'd gotten it really clean. So I removed the entire "unit" from the toilet (pretty easy to do with just two big plastic nuts & bolts, only took a minute). Put it in the shower, sprayed it all over with a cleaner, left it for a minute or two, then showered it down and dried it off. Re-attached it to the toilet and voila! nice and clean and sanitary.
As for the comfort, not really all that bad unless I take some reading material in with me and lose track of time