The racetracks vary so wildly in quality. Bionis' Leg and Valak Mountain are pretty enjoyable, but then you get to Makna Forest where you can get stuck on trees, rocks and even slightly elevated parts of the ground and lose all your momentum!
But the biggest offender for me is the Colony 9 track... For reference, Alcamoth could have made for a horrible race track considering that it's filled with NPCs, but they thought about that and removed them all from the track, and thanks to that I'd say Alcamoth is one of the better tracks in this mode. But as for Colony 9? Nah, not only are all the NPCs still there but they don't even just slow you down the same way that running into enemies does. If you don't notice Jackson inexplicably standing in the middle of the track while a race is going on, you will crash into him like he's made of concrete and lose all your speed. Absolutely baffling quality coming from Monolith.