In a future release it would be great to be able to show a bracket of dates for an K2 event.(Items added directly to the calendar have this option) Currently an imported K2 item can only have a single date applied, the "Created Date". But perhaps an option to use the "Finish Publishing" date to create a span, in case the event covers several days.
Very good support as well. Not lightening fast, but they will take care of you. They fixed a pretty complex issue I had.
Any issues I had with template interference was due to the template itself, not the module. Some templates will use too vague CSS. Like applying style to base elements like div, p, tr, etc, instead of using a specific class or ID.
It's a little plain, but can be spruced up with some CSS quite easily. I would definitely buy this module again and anyone who buys it should feel confident it will do what it's supposed to.