Hi Ron: I have LS on my 2020 2552.
Have only had a couple minor issues so far:
1) one of the hydraulic hoses was rubbing on the metal wheel well and got minor surface chaffing. I noticed this and rectified at home. It was really a Phoenix issue as I believe the wheel well is installed after the LS is installed to the frame. It was an easy fix but could have become a big issue had I not caught it.
2) small bug I have been living with: when I use LS to raise the rig, which is not very often, the limit switch is out of adjustment so that although the rig goes up as it should, it doesn't go up quite high enough to trigger the switch to turn the pump off. No biggie, just an annoyance. Some day I'll try to adjust the switch a bit.
I have been doing my own inspections on the system and was planning to stop by LS when I was in Elkhart to ask them to check the torques, but a fellow PC owner told me that when he brought his in for inspection, the way they checked the torque was just a visual inspection of the bolts which have lines painted on them to indicate original position. So now I do that too.

As far as longevity, time will tell. But my understanding is LS has been used on ambulances for quite some time.
Regarding the ride, I think it is great but admittedly have never driven a PC without it. Can say it sure beats the ride of my previous Coachman class C!