Sorry to hear you didn't get on with the MZ-S Todd, though I'm not completely surprised. You made it clear how much you like the F100, and as far as I'm concerned the F100 is the Best Film Camera Ever Made. The only thing wrong with the F100 is that it doesn't have a Pentax K-mount
I'm not surprised you like the PZ1p either. It is built like, and handles very much like, the Nikon F90X. Amazingly, the PZ1p beat Nikon to the dual-control wheel concept, which makes the PZ1p a much better camera than it's Nikon contemporary. (Otherwise it's a draw, they share the same awesome shutter too.)
I don't know why Pentax abandoned the development stream of the dual-control-wheel system. Something put them off it for the entire MZ series, including the rumored but unreleased MZ-1. They experimented with the MZ-S and it's slanted panel and multi function wheel. I think it was the right choice for that camera as it preserves the use of the on-lens aperture ring. Many photographers lament the loss of the aperture ring in the modern world of the dual-control-wheel. But it's odd that Pentax would get to the dual-wheel first and then abandon it for an entire camera generation.
One final point about your MZ-S and it's control wheels. If they are not easy to turn with a single finger, or the edge of your thumb, then something is wrong with them. On my MZ-S the left hand wheel was easy to turn (but precise, it always clicked into place.) The right hand wheel required a thumb and forefinger and a definite effort to rotate. I had my local camera shop open up the MZ-S, and they found that Pentax had sealed the wheels with a rubber ring. The rubber had disintegrated some, and the ring was catching the wheel and dragging the whole mechanism. The shop just removed the rubber and cleaned out the track, and put the camera back together. It worked PERFECTLY after that -- I could adjust shutter speed with just a flick of the thumb while the camera was to my eye. I assume I lost alot of weather sealing, but I was happy to have the camera operate as it was intended.