Anyone have any experience with this shaft?

I just installed a RB5 SR flex on an Epon 153 head, had one round of driving range, excellent feel, very smooth and easy to swing with, provided great distance as well. I like it very much so far and looking forward to play it on my next game!

Tempting to pick up one... Do they play similar flex to their earlier models?

never played their earlier models, you must give it a try in our coming game.