Based on the description on their site, the controller includes a built-in battery: "8.39 Wh Li-ion battery, 35+ hours of gameplay... "
That was disappointing for me. Specially condidering the Steam Frame's controllers make use of AA batteries: "One replaceable AA battery per controller, 40hr battery life"
AA Batteries might not be as convenient to use, but being able to replace them is a great advantage. All my Xbox360 controllers still work fine, but none of my PS3' Dualshock 3s.
The official docking station could be used to recharge (rechargables) AA batteries so the functionality could remain the same.
Trackmania requires the same precision as other racing games (I also used controller for Forza horizon and motorsport).
Bluetooth audio is a different issue, where my bt speaker adds like 400ms which.. is not suitable for anything where accurate sound matters. Even my bt headset that is meant to be good is uhh.. flawed. But noise is far more obvious than a controller being a tiny bit out.
My controller I can't tell the difference.