I've been able to get NRs to work with 28s, but only on bikes with the longer 1010 dropouts--not sure it works with the later, shorter ones.

I agree 28 makes a big difference as compared to a 23. Plus I think low gears are good for climbing even if you're fairly strong. Years ago (when I was in much better shape) I used to ride a 53/39 x 13-29 (yes, 29) 10 speed Chorus drivetrain for hilly rides in SE Ohio. Some of the folks who laughed at the "pie plate" ended up eating my dust as I spun past them while they struggled up long steep climbs in higher gears.