a6t9vette

My son got a EXP for Christmas so I decided to get back into the hobby with an EPX Pro which I just got yesterday. His feels nice and smooth with stopping, starting, brake, and change to reverse, but slow hence the Pro for me.
Got everything charged up and tested controls in the air (no weight on the car) and everything feels fine. So I took the Pro out for a test and once on the ground it feels like it's weight is holding it back and I have to give it more and more throttle then it takes off. Having never owned a brushless rig is this normal? It felt if something was wrong so I pulled the body and held it back while giving some gas and it almost sounded like it was jumping teeth but it wasn't. Is this how brushless feels and it just needs evought voltage to overcome an initial start. It makes doing and thing low speed pretty hard.
Just trying to find if this is normal or something I need to return or work to fix. Thanks for any input.