Edit. 1 year on. Still a very happy bunny. I'm editing this, however, to deal with the comment by Breadvillage below,
"It only allows one review per email solicitation. Hence, a customer who buys more than one product gets pestered with as many emails."
Firstly all review apps that I'm aware of only allow one product review per email. As for customers getting pestered with emails, it's not the case. In settings you have the option to select how many emails get sent per order regardless of how many line items were in the order. It's not as though this option is hidden, it's the first thing you see in the settings panel.