ya it is good but the problem is that it does not have free good templates nor is easy to customize.
I've found a lot of free templates for it and its quite easy to customize. And if you need help, their support team is pretty quick to respond and very helpful.
Code your own. Once you've got a login system that's stable, it's really easy to add things to it. PHP would be the best language to code it in in my opinion, it's stable and very extendible. You can write your own functions to save you having to keep typing the same code out all the time.
-Luke.