Interesting theories. In those photos, the PROS25 definitely has shorter fingers and is open wider. The 26 on the bottom is shaped like the one I have. I bought mine well used, and I just used it in a game last night for the first time. Before I started using the PROS27 Trapeze I now use most of the time, I used a Gold Glove Series GGP502-11C. It's a 12.5", but is shaped like the PROS25 above. I did remove much of the heel pad and the inserts, so maybe it opens wider than it would have had I left it alone. I have a pair of new GGP502s I'll take a look at to see how they're shaped. The GGP502 also has the dual hinge basket web. Different series, GG vs PP, so the differences and similarities might not mean much. I know the PRO502 HOH is a little different than the GGP502 - a little smaller for one thing.
Thanks for the input!