I tried meteor shortly after it was released. It wasn't clear whether there was a path to making a native app and it felt like there was quite a lot of magic going on. I wasn't sure I'd get the security right and wasn't clear on whether it could scale beyond a single server. I preferred the idea of REST because I could drop in caching proxies etc and knew it was stateless. Of course, things might have changed now.
I guess there's no parallel for react-native though, which is really the killer feature for me. GraphQL & Relay are really the icing on the cake.
