no fadec on the 10, it was straight mechanical linkage. the problem was the A/T would try so hard to hold exactly a Mach or airspeed at high cruising altitudes and with all the different disruptions like light chop, temp variations and wind changes, they would move like crazy. If you were manually flying the throttles, and you hit light chop or a slight airspeed deviation, you normally wouldnt jockey the throttles around because you know youd pass through it at some point and things would go back to normal.

then again the other airplane I fly is EEC controlled and the autothrottles are extremely well engineered. They are smart enough to know engine EPR versus matching throttle position on takeoff, and will revert to the known throttle position if the EPR's are reading incorrectly (Air Florida crash) on takeoff to make sure you are making enough power.