Bride-to-Be has been very productive for me every year for the 3 years I've grown it. It has shorter stems though. I tried 20 Ryecroft Jan and thought it was fantastic. The plant itself isn't necessarily beautiful - the leaves remind me of lettuce. Brookside Snowball and Blizzard are the other white dahlias I've had for years but neither in any year compared to Ryecroft Jan for me in this first year. I think Ryecroft Jan's blooms are way more beautiful too.
I think I'll kick Blizzard and Brookside Snowball to the curb and try to get some Formby Alpine next season. Or Coseytown's new one.
I know we aren't necessarily talking about pompons, but Bowen was new for me this year and it was super productive and beautiful. It got a blush in hot weather, which my florists liked, but if you're counting on white all season it may not be the best choice.