Personally, I group my fly rods into 2 categories : the "Preference Casting" and the "Performance Casting" categories.
Those in the "Preference" group includes most of my Bamboo rods, with the Winston LT series and the Sage SP series being the only graphite members. By and large the "Preference" membership consist mostly of members that had been in this club for more than 20 years. Incidentally, the 2 newest inductee had been a member for the last 15 years and I've not found a new member since. And I doubt I'll be able to find another new member any-time soon.
Membership in my "Performance" group however has a very high turn-over rate of perhaps 3-5 years. Right now the Sage One series is the only member.
And I will be very surprise it stay a member for more than 3-5 years.