I have never experienced the "jittery image" you describe - that is wild, but glad you resolved it with better isolation :)
As far as "lively" sound, I would attach more to tonal balance placing relative emphasis on higher parts of the frequency spectrum. Having now experienced VPI decks for over a year - I would say they generally have a dark tonal balance. Much more so with the 3D arm materials. The opposite of "lively". They are VERY reactive in audible bass frequencies if your isolation is not good enough (again, especially 3D materials) - this probably feeds into the "dark" character I perceived, but it persists to some degree even with better isolation. I ended up preferring their later metal arm wand builds.
By contrast, the Clearaudio Innovation decks tread into slightly "lively" territory. Very clean, tight, and fast in bass. Very clean midband without sounding sterile. Clean, crisp treble without sounding bright. Some might wish for more overall bass energy, but it’s enough for me. These tables are not reactive in audible frequencies (which probably contributes to their "clean" character), but rather they are VERY reactive in subsonic frequencies due to the magnetic bearing. It doesn’t affect the audible spectrum until your woofers are flapping like crazy and /or your amp is pushed into clipping.
The SOTA decks (Nova, Cosmos) sonically fall smack in-between these two. Not dark like the VPIs, but not quite so clean as the Clearaudio. Very nice "musical" balance, and with superb built-in isolation. You should still try to avoid the suspension getting excited during playback (it benefits from rigid support).
I've used a few different models of all 3 brands with different rooms, isolation, arms, and cartridges, phono stages etc. The sonic "character" I speak of is extracted and averaged from that.