Gordon Biggs also does very well in zone 3, I've only had it for about 3 years but it flowered well even its first summer. Less red and more raspberry-red in tone, the darker eye stands out beautifully. It's not a colour that I have in any other flower in the garden (always a plus for me).
Yes, a shorter daylily that ... if you don't take care with what is planted nearby... could dominate everything around it or get lost and overwhelmed by taller plants. I put it in the front of the border & combined it with Liatris, peonies and coneflowers - it seems to fit right in with a very natural look. I've not used it as pod or pollen parent, so cannot attest to that, but it definitely holds its own and puts on a show.
Unlike some folks have commented, here in my chilly northeast gardens, I have not had any issues with Gordon Biggs and rust ... I do cut back my daylilies in the fall and discard the foliage, but we average a minimum of an inch a week in the summers ... Three years ago, we hit full drought (I did give some supplemental water to Gordon Biggs that year, as I always do for first year perennials); this past summer, some weeks topped 4 inches!
But Gordon Biggs continues to flower well. I would recommend it without hesitation.