Many thanks for the replies. You'd think I'd be at my local bike shop asking all these questions, but I honestly don't think they'd know what to tell me. They're nice guys, and I love the shop, but they're all 20-something mountain biker types who tend to answer with "yeah, sure, I guess" whenever I ask them anything. Problem is, they're the only game in town--the "serious" bike shops in the big city are a half-hour drive away. And I don't have a bike rack on my car.

Your comprehensive replies have got me thinking...I'm noticing that I tend to slide my butt backwards on my saddle sometimes. It happens when I want to pedal a bit differently, i.e. when I feel like putting more forward/horizontal power into my cadence for a change of pace (Does this make any sense? I hope I'm explaining myself well enough here). I'll go like that for ten minutes or so, and then slide forward again. I wonder if I'm not defeating the purpose of the split-seat saddle when I do that, in that the soft stretch between the genitals and the sit bones are bearing my weight?

Might this be an indication that my bike is too small for me? I do have my saddle up as high on the post is it can possibly go (way beyond the factory recommended height), with only an inch or two to spare. Which is how I rode out of the shop on it last fall. Hmm....