Art,
You're right.
That looks like the last instar of the Greater Angle-wing Katydid (Microcentrum rhombifolium if you want to look it up.)
That, I think, is the last stage (of 4) of juvenile growth.
I'm sure you'd recognize the adults as they are pretty common and look like really big bright green grass hoppers and are slow and easy to catch.
They are hungry at that stage.