Sounds like Jason’s might be setup like stock with linear up front and progressive in the back if I read the charts correctly.
i can only comment on TF's, EVO's and the RK triple rates. imo the RK coils ride the best. the EVO's are not as plush as people say. id compare them more to Teraflex with both being a linear coil. obviously ride is subjective and relative to other mods, weight and the shocks you run. without changing any other mod Evo vs RK I like the new triple rates.
Probably I will experiment by changing out the shocks before the springs and also with some front hydraulic bump stops. On the road, handling is fine and with the aev progressives front and rear, it does handle on the street more like a decent euro sedan than a mushy Cadillac tuna boat or even a harsh truck for that matter. I have no trouble slinging the jeep through a corner and coming out hard on the throttle.
It is off road driving that I want to try and smooth out a little more.
As for springs. I have Synergy springs on my 2 door. I bought them before Poly specified that some were linear and not all progressive on their web site. The fronts ride and handle better than the rears. It turns out the rears are linear and fronts Progressive.
With 4.5 inch springs and a light JKU you are going to need to address rear spring perch rotation to prevent spring bow. Drive shafts and front caster/drive shaft angle balance. Without adding caster to the axle(cut & turn or aftermarket axle) you are going to be dealing with worse handling. With that much lift my ESC was always pissed off too.
Interesting observations on the progressive/linear. I would think that given a hybrid approach that the linear springs would be better placed in the rear of the jeep because that is where you pile on the load. My BMW was the Dinan test pig (upgrades were developed on my car and I got the sh*t for free) back when it was new and Steve Dinan specified linear coils in the rear with progressive in the front. Factory is progressive all the way around. Anyway, I later swapped out the dinan junk for Eibach which is a lot better and progressive all the way around. I kept the dinan-revalved konis on.
So after the shocks, I may try linears in the front, leaving the aevs in the back.
Just curious - why don't you like their coils? The shocks....are too expensive, although a great concept, but i've never heard anything bad about the coils (i have them, but haven't owned anything else so I can't compare)
I think MC makes high quality stuff and think the coils are probably well made etc. I just have not bought into their design where the top coils are always compressed (I guess, except for full droop). I will end up with progressive (or triple rate) or just plain ol linear.