As long as you don't try to do too much with Wordpress, it's a great front end to feed traffic. I tried to build a complete membership site and it caused a lot of problems due to the inefficiency of running multiple plugins, especially YourMembers, a poorly supported and flaky plugin, which won't work with Zombaio and locks out expired members from rejoining). On top of that, it got very slow and started crashing when it got more than a few users viewing video. That said, if you are a real php and css geek, you might get away with it but then you'd be modding code every time you upgraded WP or plugins.
I am now moving all my member content into PornCMS and just having public content on WordPress. You can see it here:
www.esinem.com Unfortunately, I still have to run YourMembers during the transition (still transferring content). I highly recommend PornCMS for bang for your buck and simplicity. So far everything has gone very well with PornCMS and it has been very well supported. I'm still sorting out some minor teething problems with uploads but have every confidence in their support.