I would have to say that I am in the 99% class as far as time with the Speyrod and the rest of time with single it is Bamboo.
Have been playing with several switch proto-types and the verdict is still out on those.
Have cast a Meiser 10'6" for #7/8 and was very impressed.
As for Hal and 5120 Sage I think that that is just a dream of his.
The 5120 would make it for half ponders but would skeptical of chasing anything large with it.
Would like to try one for the Yellowstone and hoppers that Hemingway wind really can cause you to reach for a Spey rod.