For karting in general. At a certain size and weight you can no longer get a front to rear weight balance that works and your vertical center of gravity is too high. This means your rear tires are stuck which requires too much steering input (toe out) which is like putting on the brakes in wide turns and you get a dramatic snap oversteer in tight turns which is hard to control. Also can’t run tires with grip because you’ll bicycle up on two wheels. If your frame is too light it will feel like a wet noodle jumping all over the place under heavy braking. Anything bigger than 1/4 mile track where you’re up over 50 mph for more than a few seconds and you have a big aero disadvantage. Kart racing is Napoleons revenge.
Don’t stress too much over what to buy, just get something in good shape with 32mm frame, med hard axle, MG reds and get out there.