Thanks for all the great advice (and keep it coming!). It’s funny how I narrow my search down to two bikes, then the more research/advice I get, the more different I find out they really are. It sounds like they each have their ups and downs, which I figured, but it also sounds like I need to prioritize my goals.
My gatherings from your collective comments;
The goal is fitness and fun, not commuting or hauling. The Giant is better for overall fitness with its speed and general road bike dynamics (and great looking). But the Trek is probably more comfortable and easier to ride with its hybrid frame, fatter tires, and better drivetrain, yet still a good trainer for a newbie because one might not take full advantage of the road-bike speed.
Hmm… I’ll be going to the shop this weekend, and I think another test-ride of each is definitely in order.