I prefer the sprung saddles over the solid ones. With the exception of the B135 the saddle springs are very stiff and serve to take the edge off of bumps and jarring.

I am a bit heavier than you at ~215# the only time I notice the springs flex is when I hit a bump or don't unweight the saddle going over a road obstruction or pot hole. To me they take the edge off the rough ride and make things a bit more comfortable. FWIW all of my Brooks saddles have been comfortable right out of the box and have only gotten more so the longer I ride them.

Buy your Brooks from Wallbike and they have a return policy that cannot be beat.

Aaron