Some are prettier, and some integrate differently, but none have the support behind the extension that JEvents does. From Geraint the founder to Tony in support, I can always get a timley and clear answer to my inquiry. And better, they'll often help you with your modules to get things to display correctly.
If you're considering a calendar extension for your site, we manage over 600 events a month and have never had a MySQL slow down ever. JEvents has never bombed or produced anything but the expected results.
Invest in your site(s) with JEvents and you will be happy after the install, that you did.