I'll put in a good word for the Katy. I haven't done the entire thing, but a good chunk of it in the middle. I think it's beautiful. I haven't toured extensively so if I'd biked through mountains maybe I wouldn't think so much of the Katy. Crushed limestone does reduce your speed by about 2 mph. But if you have a week to spend on it that should be fine, and you can always just go as far as you go and no worries if you don't get all the way to the other end. The bikekatytrail site you linked to does have a forum, so you can get more info there about services and season. I believe Tuesdays are sort of the day off for a lot of businesses, and many shut down entirely during the off season.

I love the bluffs and the river. You can see so many animals if you are on the trail in the early morning or in the dusk, so even if you aren't out biking on it early or late, head back to the trail at those times and just walk around a bit (but watch out for copperheads who like to curl up on the trail because it retains heat). There's some really beautiful birds out during the day too. Constant pedaling doesn't bother me but I ride with a consistent effort level, so when I get tired I simply go slower.

I wouldn't call it boring, but I guess it depends on what you find interesting. I find transportation policy fascinating myself, so maybe I'm more easily entertained. Anyone remember Bert's paper clip collection that Ernie thought was so boring? That's me! lol