How young? Don't roses take a couple years to really reach their stride?

Youth makes a difference. Not only that, 2 miles can make a difference too.

If you have the same sun exposure, it's probably youth. Young roses and roses getting less sun than they want may be focussing on vegetative growth late in the season.

Thanks for your thoughts, they make a lot of sense! My David Austins have been in a long time, which I had not taken into consideration, so at this point I'm going to go with the roses being young. The roses at the test gardens were totally out in the open with full sun all day; mine get about 7-8 hours of full sun a day so don't think that is the problem, and I will say my older climbers on the fence get a huge bloom in the spring and a decent bloom in the fall.

Patience...