i think the mt2 is buggy right? it's more agile because the center of gravity is lower, it's faster due to final drive ratio and weight difference, if you put smaller tire read lower ride height, it wil lower the center of gravity, but also increase of the line acceleration, and will decrease overall top speed, just by changing tires alone you can affect performance, it mostly depends on where you are racing, if it's course with lonng straights you need more top speed, if it's a course with a lot of twisty turnn you probably better of with better acceleration then speed, as for your english don't worry you are doing fine, i'am in honduras so cool.
Awesome wheels, where are you getting them?