This is the best tab module I've tried. No problems with all the browsers, exelent and fast support and a perfect integration in all templates.
I decided to pay for this extension after trying all of the other, wich presented some minor issues.
If you're developing a professional site this is the choice you must take.

This is a good extension, works as described and the support is good (I had some questions after istallation and the developer answered in time).
Works as described. Note that if you want to provide the user to add event to the calendar you must add a menu item.
Some problems if you want to edit the aspect of the calendar. It's quite hard to customize. It uses tables.
It's a good choice if you want to add interactivity and useful items to CB profiles.