As a lover of Avocado I will tell you this is good, but a bit unusual. I find my brain telling me mmmm Avocado and my mouth saying YUM Ice cream. And the two cause quite a clash to your senses. I think to stray a bit from the actual avocado flavor next time I will use a bit of coconut cream.
Doing a quick google search I found quite a few recipes for this. I will say the one main difference in David's creation versus let's say Alton's is the substitution of sour cream instead of whole milk. Not sure how much of a taste change that equates to but either way I am sure it's pretty good.