Safari has a rear Dakar style tank and a tank that fits over the front tank.
A 250 or 350 feels 50 lbs lighter due to the significantly lighter crank mass. The 500s will plow more and resist direction changes. The 250/350s are very tossable, and the power won't bully you around in tighter goings. My son can whip me on a 125cc 2t so don't think they are slow. My own lap times on a 250 compared to a 450 are the same but I turn the 250f better.
Shop the Husky 250/310 and KTM 350 too.
The Burgs were a simple tank resdeign from being excellent. As they are they suck to take apart. The 570 has great power but nobody says the 500/501 doesn't have plenty too.