I have a bad back, so I've tried about all the different spring/lift kits at one time or another...
What I can tell you is,
I put ProComp in the same category as 'Rough Country',
Rancho, ect.
If you want to feel every bottle cap and dime in the road, then these are the way to go for mall cruisers you can hang off the sides of and never get the suspension to flex.
As far as I'm concerned, Black Diamond or Old Man Emu are the ONLY companies I know of that will give you a spring that isn't a stiff as a wooden plank...
Rusty's Off road has some pretty good springs, but next month will be a year since I got my springs, and I'm STILL WAITING for all the parts I ordered or return money/credit for some shackles I sent back...
For slow speed operation (Trail Riding) it's REAL HARD to find a set of spring that aren't so stiff they will work at trail speeds, and 'Pro Comp' sure wasn't that for me in my '79
CJ7 !
I kept them about 3 months before stripping them out for a set of Old Man Emu YJ springs and never looking back!
I've got a set of 'Rough Country' springs for the same CJ I still haven't been able to sell! Exactly 3 weeks on them before I had enough and took them out, and I haven't been able to sell them (Because I'm honest and tell people they ride like a buckboard!)
The Rancho and Pro Comp springs for the same Jeep have gone out of here, but no one wants the Rough Country spring set, even with extended shackles and fresh Urethane bushings!