On our Network Pilot, the ACP1 is rated for a maximum of 12A (or 14A, the manual states both at different places and interchanges them often), while the ACP2 has a maximum of 20A (or 25A. Again, interchanged throughout the manual). They also have different clutch
voltage selections. The ACP1 is set at 12V and is not changeable, while the ACP2 has dip switches for changing the clutch
voltage (9V, 12V, 18V, 24V. The clutch works well at 9V/18V and saves an amp on the power usage in 12V/24V systems).
That is what the manual says. In practice, our ACP1 autopilot
consumes 20A in rough conditions with no problem and when I looked inside it, there were the dip switches to change the clutch voltage (and they worked). Also, the manual states to use a 25A fuse and identical wire size for both systems, which may just be laziness or may indicate that they are both the same internally.
So for a 12V system, I suspect your B&G rep is correct. I do know there isn't any obvious way to change our ACP1 to a 24V system,and they do not give any instructions for changing an ACP2 unit between 12V and 24V, so it may automatically switch when 24V is applied.