Maybe brittle is not the exact word I am looking for. What I meant is "non-flexible" (impliable?). Aluminum does not like to flex and return to it's original shape, compared to say steel. It will flex, but then remain in that position. Of course steel would be far to heavy for this application. I have never snapped or exploded any aluminum bindings, but I've bent every aluminum binding I've ever used (Targa, SPI, Raiden, etc). This probably won't happen unless you are riding pretty hard though. What you mention about Ride's bindings bending... um, isn't that a big problem? I'm sure you've seen lots of broken Polycarb as I have too - because like I said most snowboard gear is crap. So to sum it up, Aluminum won't snap but will often bend / Polycarbs won't bend but might snap.
ukaszeklp Cartels and Malevitas are definitely good bindings. I personally don't like Burton's highback hinge (how it always comes loose) or their ankle straps, but besides that, those are really good bindings. I have seen a handful of Burton's baseplates snap under hard riding, although it has not happened to be before. Luckily that's rare and they have a lifetime warranty.
This year I'm going to give Salomon bindings a go. It's very limited these days when it comes to non-aluminum bindings with good features. (off the top of my head: Salomon, K2, Flux, Burton, ?)