Secure in this day and age means little I feel, with our Discord channel you can only access it if I or one of the moderators invites you it's our little internet fortress of solitude and I'll always keep it that way. We also ensure that everyone gets along and if they want their own group areas then I'm fine with that too.
The problem I see with Twitch is that you can join any channel you like and then if you want bonuses you have to subscribe usually for something like $5 a month. I'll be sticking with Discord as it matures and eventually open it up to more and more people, I'm really looking forward to their upcoming streaming features as we play quite a few varied games we're not just one trick twitch ponies.