4x2 chassis is the cheapest of all the chassis and also bigger tank capacity with a normal turning point but the harder part of it while having a load and turning quick to 60mph it could turn your truck down,
6x4 chassis is used for heavy loads with great handling on it and specially used for off-road but lower turning point without load,
6x2 (6x4-2) chassis has more turning point for unloaded/forward driven with trailer and cheaper wheel repair ; and
6x2*4 is the best for handling heavy loads/off-roads, have better turning point, fuel saving, nut much wheel repair and fuel capacity.
For my experience, I would like to share my opinion about the chassis options: 4x2 is the cutest and can have the shield/guard for the fuel tank, 6x4 is the most general type of chassis where I'd prefer to use in the first time I'd use it, 6x2 (6x4-2) is the worst and I hate when I'm turning with this chassis, the trailer always stuck in the edge of the turning road, The Best I would recommend is the 6x2*4 because it has the feature to have the highest turning point but the trailer acts to follow delayed to not experience hang on the turning road and also the trailer is more likely stable but delayed follow.