Quite respectable Petrolhead, i would have expected much worse.
Maybe the grade of aluminium, i always get the cutter deflecting to one side.
Those that intend buying new hole saws the Bosch quick release and arbor are the best, last longer and cut a bit quicker than Starret etc. Have and use both types of Bosch White and Blue for drilling through to 18mm thick in 6082.
I just the hole saw to cut a hole then bore out which brings i back on centre, 18 yesterday and close on 14k holes so far, cant go wrong or i would have changed 25 years ago they work within reason.