SawTroll
Information Collector
Your concern with the auto tune is unwarranted. The coil has a lifetime warranty or up to seven years after the last year that model was produced. So if you have a coil failure - it's free. If there are only newer coils available that don't match your carb - then the carb is replaced under warranty also! At most, the only thing you may have to pay for is the carb when out of warranty, the coil will always be covered. I think the last I saw the carb came with the autotune on it and it was in the vicinity of $70-90, which is less expensive than some conventional carbs out there. You worry for nothing my friend.
They have been developing the autotune at least since 2005 (pre production 575xpAT tested), likely longer, so I don't see any reason to worry about it. That test resulted in the 576xpAT.
The one on the 560 and 550 family saws have the second generation production ones.