I have two B67 saddles. I loooooove the springs, but I tend to sit "hard" on the saddle anyway which springs really help. Yup, they do add some weight. Grant Peterson feels there's no difference in function between the B67 (springs) and the B68 (no springs). He's not a girl. I'd go by what LisaSH says or what MimiTabby says before I go with what Mr. Rivendell says.
My 2nd B67 came along for my 2nd bike just cuz I loved my first B67 so much, and saw no need to mess with success. (once I figured out the creaking noise issue, there were no No NO problems!)
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson