I'd be very surprised if you would notice any sort of difference in connection speed at all whenever the system would authenticate. (if that's really all it does). It should be a blip and that's about it. If they did any more (or at the very least anything noticeable), you'd be SURE to hear about it because the internet would explode. If it's an always on connection vs pinging every x hours, that's where you could potentially run into problems. If it requires an always on connection, I doubt all they'd have in some kind of heartbeat service. It'd likely be constantly feeding back some sort of data. So basically my point is that 1 blip every once in a while isn't going to be noticed at all. Constant data is what you'd have to worry about.

Of course, this is speculation too but I think it's pretty reasonable.