Purchased this based on the examples featured on their 'Demo' page. But was left feeling disappointed.
Using K2 2.5, it will only source K2 items from child categories, not from a parent/root category. And the four themes look very basic, and will require css editing to sit well with almost any template.
And to top it off, their contact form for submitting support tickets does not work!
A nice idea, just requires more work!