I agree with Nick, the IR battle system in the original FOV tanks was quite nice. Team 1 was free for all, plus specific Teams 2, 3 and 4 that would reject hits from other members of the same team. It would be great if this were maintained for backwards compatibility for those that still have the old FOV models.
The FOV protocol was also much more sophisticated than any other brand - header plus 8 bits of actual data, meaning the same FOV protocol could actually transmit up to 256 codes (but it only used numbers 80, 85, 90, and 95).