I dislike the AGX simply because their adjustability sucks. All they offer is dampening control so they are either stiff, or stiffer. Rebound does not come into play with the AGX and there for as you increase the stiffness the rebound stays the same.
From a handling point of view. S13 owners already know they are bad for under steer and personally I felt the AGX made it worse if anything because they were always to stiff from the dampening with not enough rebound. And the only way to even remotely deal with it was to run the fronts set @ 1 with the rears set @ 8 which was extremely uncomfortable to drive.
So I got rid of the AGX and went back to my stock struts/shocks until I got the monroes from Nick and goddamn was I ever impressed because the first thing I noticed was the under steer was not near as bad. So I then went with a bit more camber in the front and it got even better which is another bonus the Monroe has over the KYB is their camber adjustable where as the KYB is not.
Cost, Monroe wins as their cheaper and still offer a lifetime warranty. Overall Features Monroe wins again as the Sensa Trac blows the AGX out of the water. When you buy the AGX, your buying the KYB name and that is all. Performance wise they suck on the S13 atleast.
Either way… some Stance GR+ Pro Coilovers will be going on soon enough to see how they can compare 