I did hundreds of auto-x before moving to HPDE and eventually to road racing. I found AX was both good and bad. More good than bad in that you are used to the environment (Heat, helmet, car control, car prep, etc). The only downside is that AX people are generally not nearly as smooth as a pure Road Course person in the begining, they need to fight the urge to crank the wheel etc.
Overall any track time be it Autox or Road Course is good track time.