This is our experience and opinion.
We bought our van (01 E350 7.3) as a Quigley then had Chris convert it to his 4" suspension. We considered getting Agile offroad's RIP but ultimately went with the full replacement for easier acquisition of parts and it's simply one of the best. Our van drives entirely different then when we purchased it in San Francisco then drove it home to Florida. Freeway speeds with the Quigley made her a bit squirrelly, breaking 75 on the speedometer started a shim... more likely death wobble. At home I crawled around under it and found our torque arms were cracked. I had a local shop do some repairs, an alignment and they added a nicer steering stabilizer... no change. We started emailing Chris which resulted in us deciding to swap to his system. Driving her back to Florida from NC was a wonderful experience. We've since gone back for some additional work and drove through the winter storm early last week. No snow driving experience at all, she performed wonderfully and we felt completely confident. We absolutely love driving our van after Ujoint did their thing. We have the 4" kit which makes our turning a little wider than the 6", we'll be shipping across the Darien Gap and wanted to ensure it'll fit into a container, we do love 35s though. We previously owned a 2012 Ram 3500 Crew Cab short bed 4x4 and our turning radius now is only barely wider than the truck. U-turning over three lanes is easy, two lanes not really possible without taking the shoulder or sidewalk. The brand new truck couldn't do two lanes either, it was on stock 29s while the van is on Toyo AT II 33s. Our ride is tighter but we're still building out the interior. Once complete we'll upgrade the springs to dial it all in.
Bottom line, we drive her on the freeway one handed just like every other car. When it was a Quigley we had white knuckles, literally (hand cramps and all). We've yet to add some real miles off-road, that will change once we begin the Pan-Am.
Definitely ride in one, going to lunch in V5 immediately put Mandi at ease over the expense.
-John