I thought the Q stood for the adjustable electronic speed control,
But I googled the atf e, and that had the turndial aswell, perhaps they just added the Q with the TS saws, and there are plenty of differences between an atf 55 and a ts 55. (I couldn't find a atf 55 eq)
Just some random ones: springloaded riving knife, plug it cord, toolless adjustment to guiderail, easier bladechange (the green lever locks the depth and the bladerotation), splinterguard on the other side of the blade aswell