I have the Flyer and the B67. The Flyer is just a B17 with springs.
It was giving me hip and low back pain. I got the B67, and if I can survive the break in, I can notice an improvement so far with the hips and back.
You should also consider the titanium railed B17 if you are under 200 pounds.
My 2 cents is that if you have your bars roughly even with the saddle, the B17 often works. If the bars are more than an inch or two higher go with one of the wider ones. Maybe. If you are using a roadie position, one of the more agressive saddles might be the ticket. I am switching from roadie rims to touring rims, and putting on wider tires to boot. I may switch back to the Flyer in the spring to see if that helps. But for now I am using the B67.
Just so you know, a couple weeks ago i did 66 miles on the Flyer.
I couldn't have done that on most saddles.