From experience they get a little squirrelly on ice. The back end will slide very quickly, like any thing with that short a wheel base.
Loved mine till I wrecked it.
The flipping over thing was the samurai and the tracker/sidekick was supposed to be better.
Check out
Zukiworld for specifics.
ETA: trackers are sidekicks underneath, not Samurais. So much so many call their conglomeration of parts-built ones TrackKicks
For that price you have a lot of $$ to play with for upgrades.
It really depends on which model the guy has (4x4/2x4, manual/auto, and engine size/ type)