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.
I have to say, this situation has improved enough that I've had no problem using BT controller connection.
We're talking about games like Elden Ring, Enter the Gungeon, MGS:Snake Eater Delta.. and reaction time definitely matters for those games. One controller even came with a 2.4ghz 1000hz dongle, and it seems the new controller will probably have an option like that if the GabeGear has the hardware built into it: "Steam Controller's wireless adapter is built right into Steam Machine for direct pairing."
I realize that. But that's just for that machine, but I'm speaking for arbitrary devices.
The protocol hasn't gotten faster in the last few years that I know of.
I've used several with different devices, but most of my direct comparison experience is with an Xbox series X controller paired to the Deck via BT and by dongle, and it's very noticeably more laggy with Bluetooth. I've only occasionally tried others, but every Bluetooth-connected controller I've ever used definitely has a noticeable delay.
But the controller comes with the high speed wireless puck. That puck works on anything. I don’t see the problem.
My point (the part I quoted in my original reply) was that you would need the puck plugged into the device you're playing on, assuming you don't want to deal with the delay.
So if that's not a problem for you, then that doesn't apply, but I assume most people will want the fast connection.