Even those who have received a non-pro car would still be in the three-month trial at this point. So I do not believe anyone has heard the actual non-pro system yet.
I was in the same boat and ultimately decided against the Pro - I figured worst case I can upgrade to it later (even thought it may cost as I had legacy pricing) but it was a worthwhile gamble. As long as the regular sound system is good (should be given the name is "Surreal Sound"), I can likely manage.