I only have one HL and I use the DBC with it (the StuG). There is slight lag between the RX-18 and the DBC, I chalk it up to power draw. It's certainly more evident as the battery discharges.

I experience it on firing the main gun. The recoil and flash unit will function every time, but the sound and IR is on a very slight delay and may not trigger. It probably skips every 4 or 5 fires. I haven't noticed anything in terms of driving, except the right motor engages a hair behind the left, which is correctable with trim.

All bets are off when the battery runs down, usually stalling under load and restarting. Again, I haven't noticed driving issues, but that doesn't mean they aren't there, I haven't paid that close attention nor have used the StuG much yet. I'll certainly pay attention next times it's out.