I'd probably bought the Ranchos based on your inputs and once I saw that the Strutmasters kit is for both Navis and Expys. So far it's been better than expected. The ride height is definitely higher than the AS both parked and fully lifted to regular ride hight. I personally like it though. It looks more appropriate for a full size SUV.
The ride quality is good. I was concerned the extra weight of the Navigator vs the Expedition show but there's no bouncing as some people mentioned with lower end kits. The OEM air suspension absorbed quick bumps slightly better but with worn OEM shocks. Overall the ride quality wasn't really noticeably better. The new shocks in the coil struts definitely improve some aspects of the ride.
My Mechanic was surprised that I didn't just have him fix the leaky bag but the constant failures on solenoids, ride height sensors and the worn compressor constantly draining the battery aren't worth the only slightly better ride quality.
I still need to install the module from Strutmasters to get rid of the dash warning but other than that, this is a more worry free ride when you head out to remote locations with family.