Thanks for that input. I'm likely going to put a Vivid coil on it to start and likely update to a 170mm Zeb a bit after and then see what I think and go from there.I have the Cascade link. It's not a huge change on the HSL since it's already a pretty progressive bike, but it is noticeable. I had to add 30 PSI to my Vivid with it. It's more active off the top, and more bottomless at the end. I'd say it pairs well with riding aggressively and a burlier build. Not necessary with the stock Lyrik/SD setup.
There will be a new X2/DHX2 this year, lots of photos of pros riding it already. Looks like some larger changes in architecture rather than just minor tweaks.