Update: Bicycle Purchased
First off, many thanks to everyone who replied to my questions! I wanted to update this thread just to let y'all know what I decided on :)
I hit about three bike shops and rode at least 15 bikes. They've changed a lot since I last did any bike shopping!
Some general impressions:
Riding a couple of mountain bikes basically ruled out anything with front suspension. In the price range I was looking at, I couldn't lock out the front suspension, and I'm heavy enough that every time I hit the brakes, the front suspension compressed. I felt like I was going to fall off! More importantly, I felt like I didn't have enough control. That also ruled out the "comfort" bikes.
I discovered that I don't like push-lever type shifters. I do really like the twist/grip shifters though. (I'm *so* putting a set of those on my Schwinn!) But the right hand is backward - that's going to take some getting used to.
Most of the bikes I rode were... useable transportation. Light, functional, but rough and, well, they just felt cheap. I felt like they would shake themselves to pieces. Sort of like a Geo Metro. The more like this that I rode, the more I think I got an absolute steal on my old Schwinn.
The Decision...
I rode a Kona Smoke, and I barely had it out the door before I was in love. Smooth, solid, quiet, and shifted like a snap. A long step above anything else I rode. It's a little long (I like to sit as close to upright as possible), but we swapped out the stem and moved the seat all the way forward, and it fits pretty good. The dealer also threw in a different set of tires (wider, with a Kevlar belt, good for the Houston bike lanes). With the dealer markup, tax, and adding a rack, I just squeaked in under my $500 maxiumum.
I had originally intended to get a bike I could take off-road. The Smoke just doesn't have enough ground clearance for that - and I knew that when I bought it. I've managed to dig the pedal into the ground just turning a corner, so I'm teaching myself not to pedal through sharp corners. :) Instead, I'm going to make it my main commuter and grocery shopping bike, with the Woodlands as a backup if I need repairs.
I'm also going to start working on the Woodlands to get it back into trail-ready shape. At a minimum, it needs new brakes, cassette, and crank. (I didn't realize how bad those brakes were until I rode a bike with good ones) That'll be a fun project!
So, anyway, long ramble over. Thanks again for the suggestions, and for all the information and advice available in these forums!