The only downside I can see with it is the fact that your board cant bend where the channel is, with my board being a stiff type of board it wasnt a hassle, if you ride a butter finger i think it would suck.
The board can't bend at the channel? Sorry ETM but you are grossly mistaken. I ride the X8 and it will most certainly bend on the channel area.
Anyhoo, ot the OP I've been using the channel for 2 years now.
As far as bindings go, I've used both the Cartel EST's and the Triad EST's. Triads win, virtually same response but more comfy on the feet. As said before there isn't a "best EST" binding, more preference, yes there's higher end models, but again it depends on your riding style.
The channel is just as strong as inserts, so don't worry about that, never had any issues with mine. You can use other bindings on a channel board, but it defeats the purpose of the channel. If peoples idea is that they are buying a board with the channel to be a better board and buying normal baseplate bindings they are not experiencing the way the board was designed to work. So far flows and drake bindings will work, but again, spend the same amount of money you normally would for bindings on last years ESTs and ride it correctly.
Too many people think the EST/ICS system is just about adjust-ability, but it's more than that. You are standing on a thick pad (unless you're using superbeds) and there is nothing other than that between your feet and the board. It's so much better than hard baseplate bindings, especially landing hard. There are also on-board markings for stance width, and center placement (tip to tail). It's very easy to get the stance perfect.
The board you got is a blast to ride, grab some EST's previous years and have fun with it.