Howdy Bill,
I am happy you are enjoying the plugin thus far!
Our Pro widget actually does use a different stylesheet, and probably will look much better in your current calendar. There is a somewhat common issue with the headers being a different font size in the free version that the pro one does not experience.
However, that is not quite intentional. We do not mean for people to upgrade to Pro just because the fonts aren’t perfect. In fact we’d like to eventually update the free one a bit to make it look a little nicer. The free version is not intended to be a “trial” of our plugin, many organizations large and small use only the free version and with great success. The Pro version is simply available if you need the extra features or want access to the premium support area.
If you are familiar with CSS it should be pretty easy to alter those headings. If you’re not familiar you might checkout WordPress.org: The Events Calendar. There is a large volunteer community there who can assist. Or, if you were already considering Pro it might be a good time to buy a license. It will likely fix this issue in addition to adding tons of features, and you’d have 30 days to return it if you’re not satisfied.
Does that all make sense? Will that work for you? Please let me know.
Cheers!
– Brook