I've used many CMS's over the years: Wordpress and a few custom-built CMS's. Here are the problems I've found with those two:
1) Wordpress: You must make sure to constantly update to the latest build, and be careful what plugins you install. Because it's so widely used, wordpress is also (I've found) the most hacked CMS, because everyone knows how it works and that everyone uses it. And plugins may seem like the a boon for non-programmers, but be careful what you install, because since you don't always know who's built them or how secure their scripts are, that's another opportunity for exploits and hacking.
2) Custom-built CMS's: Unless you have a full-time programmer on your team to constantly update the scripts and harden security, you're just asking to get hacked within a couple years. And not to mention, every custom-built CMS I've seen has sucked-- unless you have a whole team of programmers and a whole lotta money to build a bunch of custom functionalities.
I've been a long-time user of ElevatedX, and I don't see myself moving to any other platform any time soon. The amount of features are robust and extensive-- it's a great out-of-the-box solution for a porn star looking to get a membership site started, and for a company like mine that needs extensive features and custom functionality, the amount you can do with it is endless. And with their whole team of programmers constantly pushing out updates, I almost never have to worry about security or bugs.
I'm mainly a front-end developer, with mediocre PHP literacy, but you can see for yourself how much I've been able to customize their CMS:
CockyBoys