Let's talk handlebars....(long)

[KnottedYet]

If your hands are starting to protest after 15 minutes, I'd blame the bar shape. That's instantaneous enough for me. Compare the heights of the bars with your Trek, just for jollies. Also compare the distances from the seatposts to the bar clamps. Unless they are radically different, my bet is the shape of the bar is too fat for your most efficient grip, if it's biting you after only 15 minutes.

With a bike shop fit AND a PT fit on the same bike, it's probably safe to assume that whatever you need to adjust is kind of subtle. Trying to find cheap ways to experiment is the tough part!

And with the spondy, please do be careful if you try lowering the bars. Raise them all you want, but be cautious lowering them. You can ask your PT to measure your stable torso angle, and just make sure you don't go lower than that. Bear in mind that angle can change as your core strength changes.