This is a great product with a good solid set of features and well thought out design. It simply does what it does really well and it looks good on your website. Installing and set-up is quick and easy. The support is fantastic and fast. I've been testing the Joomla 3.0 version and has found it very stable.
I've tried a few other commenting products and this is up there with the best. You should seriously give it a try.