I've got one too for my TB. Very comfy and holds me in place when she's having a "speshul" moment (like broncing whilst heading down a very steep hill!).
What are the panels like - are they quite broad, or more narrow? I've never really looked at them properly before, but having considered that my mare is probably more of a wintec than a thorowgood shape, and I would prefer leather in the long run, I wonder if they may be worth a look.
They are fairly broad. My mare has quite a flat, wide back and she's really comfortable in it. Neither Wintec or Thorowgoods fitted her as well as the Collegiate.
I too would vote for Collegiate. Each of my beasties has a Collegiate GP. They seem to be fairly straight cut but that suits my shortish legs. I like the plastic trees - the saddles are light enough to carry on one arm without effort. And I have had occasion once to get the gullet changed when my mare had lost her excess weight.