My TC3 is still my best VTA car.
I've got a TC
5 VTA car that I've also been running on and off trying to get it to at least match the TC3 in terms of handling and overall performance. For whatever reason, I've not gotten there with it. I'm still faster with the TC3. Is it the belt vs. shaft? Dunno. Same motor, so I know that's not the issue.
TC3/TC4 are great VTA cars!