It's a good idea if you're 100% new to server administration and if you have custom stuff, if your server is 100% vanilla (no custom scripts or anything) then you'll probably be fine, but if you're not beaming with confidence, I would do a beta. In general beta tests are generally done to check balancing, receive criticism on features or get feedback on possible improvements in general, and to test for bugs. For RO, it would be primarily bugs.