I did a back to back test, Mach e AWD followed up by the Q4 E Tron 40.
After the drives the E tron won out.
Having owned quite a few German cars, the Audi was very much in keeping with them. The ride and seating was much firmer, something I like, the Mach e just felt soft.
Also, a personal preference, the conventional instrument display of the Audi was better. I'm not keen on the tablet style middle display, plus the Mach e, has a small instrument display behind the steering wheel.
Each to their own. The Mach e, wins out on kit though. Heated front windscreen, heated steering wheel, foot sweep opening tailgate and AWD at a lower price point.
If you can get to drive both on the same day, I'd say do it.