I use U3 mostly. U9 is just way too perky for me, often spinning the wheels at the lights or cornering.
I use E9 when I’m reversing my boat up my fairly steep driveway.
Great little gadget for not much money.
I had my engine remapped and a throttle controller installed, no exhaust mods and couldn’t be happier with the result. $1,500 for the remap and $200 for the controller.