XRAY - Model racing cars

What stock motor is the best or the fastest for running the 007 brushed or brushless?

Are drivers changing to lipo battaries yet and r they better?

And is it true that when You have foam tires of a particular diameter.You have adjusted your downstop settings and your ride height settings.There is mm of front droop
After you race the car for a short time the foam tires wear down to a smaller diameter,which decreases the ride height.So you now adjust the shock
spring preload to increase the ride height to a proper value again.
Increasing the ride height causes the chassis to raise up slightly,which decreases the amount of space between the downstop screws and the chassis.
The result is that the droop values are now reduced,so the car will handle differently.
(In extreme cases when you have to increase the ride height a lot,the droop may completely disappear as you increase shock spring preload.If
you increase the spring preload so much that you remove all droop,the ride height will not increase no matter how much preload you set since the
downstop screws are tight against the chassis and do not permit the chassis to rise).
In this situation,to maintain a certain amount of droop you need to loosen the downstop screws slightly as you increase the ride height.You must
alternate between adjusting ride height and downstop settings to maintain a particular droop value.This must be done equally on left and right of the car.

So what is the best way to run on carpet foam or rubber tires?