I'm using Simple Commenter to get feedbacks on websites in development, and early launch's. It's easy and straightforward to implement, lot of customization, and over all, for the prize, an amazing value.
I'm thinking on other use cases - i just have to switch to think more user engagement.
And, Aleksander is very prompt to help and react on feedback: you really feel that this product has a great future with that dedication !
Very happy user here.