"I haven't come across a pole bean that is as tender as a bush bean."

(ROFL) :-))

Sorry, no offense. As a collector of pole beans, that statement just struck me as hilarious. I think I'm back in control now...

But seriously, which pole varieties have you tried? I find that the size, yield, and flavor of pole snap beans are hard to beat. There is an incredible amount of diversity available. You will probably get a lot of recommendations, here are some of mine:
Emerite - filet type, round very straight pods, very firm, outstanding canner & freezer
Fortex - filet type, round 11" pods (!!!) excellent raw, good freezer
Goldmarie - flat Romano-type wax, 10" pods, delicious raw
Pole Romano - flat pods, sweet, meaty flavor
Rattlesnake - round pods, good flavor

These are all stringless or nearly so. There is also a great Romano-type heirloom available from many on this forum (Bosnian Pole) that is completely stringless in all stages. Garafal Oro is another Romano-type with high yield & great flavor.

HAHAHAHAHAHAHA!!!!! WOW! How I didn't see that is beyond me!!!