Ok I get it. It is typical of either a slow catching pid as defined in the aircraft.cfg section, or a slow update rate of the gauge somehow (that is FS is not refreshing our GNS V2 at the normal gauge speed - 18Hz). Can you cross check there is no "gauge update rate" value in your panel windows, just to make sure of this?

I;m not seeing anything like that in any files.  Seem to all be just window placement values in the panel.cfg.  As an aside, I have the F1 GTN, and it does not have any deviation/tracking errors and updates rather fast, even in turns.  The A2A Comanche AP is said to be archaic, thus won't negotiate hard turns in TRK modes, thus one must use HDG or ST to recapture the DTK, but the GTN will only overshoot a mile or two (IIRC) and reestablish pretty fast.  This being tight turns.  Less dramatic turns don't deviate as much.  I don't see any values in the CFG files for this plane that would make any difference in the ability to track, regardless of GPS input.

I'm glad you're saying! Apart from the hiccup you are experiencing, the RXP GNS V2 A/P is very precise and follows curved tracks accurately, and almost never overshoots! Have you tried in another aircraft than this one to compare?

1 hour ago, RXP said:

I'm glad you're saying! Apart from the hiccup you are experiencing, the RXP GNS V2 A/P is very precise and follows curved tracks accurately, and almost never overshoots! Have you tried in another aircraft than this one to compare?

I will try it tonight.  I haven't had a lot of time.  I'm not doubting the GNS, the old GNS in FS9 was perfection.  I'd still like to see the A2A GA work well with it too.  Since DF is no longer a player, I don't too own many other GA add-ons now.