Your description of your VX's ride sounds like the way mine gets when it's low on nitrogen. Low N2 allows cavitation and since dampers don't damp very well when they're filled with froth, the bump stops get a workout - and you get a sloppy, slammin' ride!

If your shocks aren't leaking fluid, you might want to try adding some N2. There's not really a test other than check for fluid leakage and gas pressure. If they're easy to compress or don't extend at all when you take them off then you know they need N2! Just pop the caps off the top to reveal the Schrader valve and pump them up to about 250psi and see if that helps. If not, then either the internals are worn/ fluid has gotten thin and you need to rebuild or you just don't like the OEM ride and you need to get a set of aftermarket shocks.

It's never going to feel like a Caddy though no matter what shocks you put on it. The torsion bars in front make for a harsh ride over sharp-edged bumps etc. and the short wheelbase makes it pitch more than most other vehicles.