Did you have a specific issue or conflict with another plugin? No plugin can guarantee that it will work with every other plugin and theme out there since many plugins and themes call jQuery incorrectly or make certain types of requests that cause conflict with other plugins (not just Event Espresso).
The features comparison is on the Download page: http://eventespresso.com/downloads/ which is an easy-to-find, top-level navigation link and also linked to from many of the other pages on the site.
If you are posting about Event Espresso addons, you won't be able to get support here, as this version is the free, Event Espresso Lite plugin which does not support any of the addons. If you post your question to the forums, one of our support staff would be happy to answer any questions you have: http://eventespresso.com/forums/