A few months ago my tranny was 3 quarts low too. I was topped off. My tranny was slipping/bucking between 1st and 2nd gear. I have 130k miles. A year earlier I too had burnt transmission fluid and was told not to replace even one quart as like you said, probably do more harm than good. Well, I've since driven nearly 2,000 miles with the 3 new quarts and it's shifting like normal. No more slipping. I'm going next week for a filter and fluid replace. I agree with Ldub and take a wait and see attitude. Don't fear the worst just yet.