I've done quite a bit of Ember as well, and lately I'm kind of liking React's approach much better. It composes well with many routing/model solutions, and keeps the 'run loop' isolated in the view layer.
There are some really good cheap prosumer level EEG devices on the market now, for example the Avatar EEG (http://avatareeg.com/) and a few of the Emotiv devices.
I've been working on a side project (https://octopusmetrics.com) that allows you to connect these devices to your computer to record, visualize and analyze your EEG data in the browser. I think it's great that there are people out there thinking about how to do this more cheaply as it'll bring _real_ EEG devices into the price range where it'll be more available to hobbyists.
How do you handle when Heroku sends a SIGTERM to kill your process? I couldn't find a way to preempt running workers, so everything running on Heroku has to finish within 10 seconds or you can lose it.