The EVOL R's give you control over the rebound side of the valve stack as a needle-valve bleed that bypasses the valve stack. Which also has a minor effect on the compression side... but they are tied together you cant adjust the rebound without affecting the compression.
In 99% of the cases.. once set, the Evol R will not need to be adjusted. For most people a model specific set of Float-2's will give you all that you need... especially if you buy them from a dealer that will valve them specifically for you with a valving satisfaction guarantee.
For hucking... it is true that the the floats can ramp up if you put a good amount of pressure behind the IFP in the EVOL chamber.... Triple rate springs, like the ones that come with the EXIT shocks do the same thing... plush initial ride with a stiffer finish.
I have had the Float shocks, Float 2's, Float EVOL X's, EXIT X1's, Ryde FX rebuildables, Zero Pro's, Walker Airs, Walker Piggyback Needles...
I have had great luck with all but the Walker Air shocks... all of them were made for my machine specifically and valved for my lighter weight..
There are plus's and minus's to both shocks.
If you blow an air sleeve seal on a float.... you are limping home... less likely to break a spring. An air shock gives you the ability to adjust the pressure and, with an EVOL chamber equipped Float, give you the ability to fine tune the end of stroke character of the shock.
The X1 gives you precise control over the compression side of the shocks travel, the EVOL R gives you control over the rebound... (as I said before, some compression changes, but they are tied together... stiffen the rebound and you will slightly stiffen the compression.)