I have JT Strongarms on our Gateway and, while it helps, does not eliminate the shimmy from just walking through the RV...
I agree with MMGliderPilot in the JT strong arms help a lot but the rig still moves. I would assume until I take the weight off the wheels and axles I will always have movement. The only thing to fix that would be a hydraulic system.
Shaking will still occur to some degrees even with the wheels off the ground. I don't care what some have posted about the KingPin tripod. If you utilize it correctly, it works just as good as anything else.
So you still shake with a hydraulic system? I have the sidewinder on my unit so the simple tripod wont work too well. I would have to modify it slightly to fit.
Winfield x brace reduced shaking by 70 - 80% on my rig