My experience, with the Timbersled front, is that adding negative camber helps a lot (top of the spindle angled in). I backed the lower ball joints out 1" on each side and it made a HUGE diff. Riding others w/stock geometry, I feel like I'm going to come off the sled. On mine, the twitchy, bar slap is gone.
i 'unhooked' mine for 1 ride (in spring/setup snow). using stock shocks, cranked to max spring tension. it rolled too much for my liking in these conditions/shocks.
w/ floats, or stiffer shocks/springs, i think no sway bar will work fine.
till then, i'm leaving mine hooked up...for the spring riding.