Sprung saddles have generally been intended for upright bikes (like the classic English 3-speed) and casual riders. While the shock absorption of springs might seem like a good idea, as you develop riding style and strength, they should become unnecessary. If you are on a well-fitting road bike, you won't have that much weight on the back of the saddle, where the springs are. And your legs become your shock absorbers. So I would say they weight penalty is definitely not worth it. Unless maybe you intend to tour on really bad roads.

I used to know people who soaked their Brooks saddles in boiled linseed oil and beat them with baseball bats to soften them up. Now they come presoftened. Cool.