Themeing or make any customization isnt easy. Predesigned nice buttons and boxes dont work with any template framework. Their Demo is done with rockettheme and if you use rockettheme, then you will be safe. They have support for other templates frameworks but in reality it dosent work.
Support is so-so.. sometimes they answering fast and solving your problem but sometimes not..and sometimes they just close your support request and you must start again to ask same thing.
So far there is no multiple prices options for events.
Please investigate what you will buy, because you can get suprised. My first suprise was after buying it that there wasent frontend management for events.. when users started to complain then they did it 6 months later. This is just one example.
So most of the times it works, but be prepare for suprises.
If there is any another good events management then i would quit ohanah.