You should be able to get a pretty decent polar alignment with the AZ-EQ6 because the altitude and azimuth adjustments are easier to use and make precise adjustments. On the regular EQ6 it's more of a challenge
Regardless, a 2-star alignment improves things significantly over a 1-star alignment as you've given it a second point of reference. Unless you've got a near perfect polar alignment, the extra few seconds to add the second alignment star make an appreciable difference to the goto, though not necessarily the tracking.