Turns out the right rear toe was out. $90 later I'm all fixed up.
Think the OE all seasons are just more sensitive to alignments. Even after the alignment its a bit twitchy on center.
The misalignment would have caused premature and uneven tire wear. You probably got used to it when the tires were mounted before, and/or the problem was magnified by the tires being in different positions after being rotated.
Different alignment and forces on front and rear tires result in varying wear patterns. After rotation, the tires are in positions where their patterns may be the opposite of how they want to wear in that position. So they feel odd until the wear pattern reestablishes itself. Not to mention the variation between sets when we do summer/winter swaps. This is why rotation intervals are so short - to minimize this position-specific asymetrical wear. So the greater the amount of wear resulting either from misalignment or long rotation intervals, the worse these effects will be.
And the purpose of rotating tires is to make sets last longer because it evens out the wear patterns. Without rotating, you'd bottom out part of the tread on some tires long before the tread of the whole width of all tires in the set are worn out. I'd bet that cars with more extreme alignment settings have shorter rotation intervals.
