I'm the Node platform owner at Heroku.
Great timing on reliability questions - I just finished writing an incident report for Node! All apps were up, but about 44% of deploys failed for 1 hour on the 18th this month. That's the only incident report I've had to do in the past six months:
https://status.heroku.com/
Our support team is amazing; we have several node devs on the front lines and anything they're not sure about gets quickly escalated to me. One of my favorite things about Heroku is that all customers - paying or not - get real support from full-time staff with deep experience.
Heroku also works great with non-node apps, as you mentioned. We have hundreds of customers running PhantomJS and doing some pretty incredible things with it (like spinning up temporary dynos to walk their content and pre-generate server-side data for client-rendered single-page apps). PHP, Java, Ruby, etc are all first-class and with official buildpacks - plus, since a buildpack is a simple bash script, you can write one for just about anything:
https://github.com/hone/heroku-buildpack-jsnes
The biggest reason I see folks hacking on less solid services is price. I think we could do a better job of making clear just how far you can go, for how cheap, on Heroku (I didn't realize myself until I worked here). Unverified accounts can run 5 free apps... and verified accounts can run 100! Each app gets 750 free dyno hours each month (there's only 744 hours in a month), and each dyno can handle really amazing throughput with node. To test for yourself, you can write a 'hello world' app, add the free blitz:250 addon, and then slam the app with 250 concurrent users to see how it holds up with nearly a million requests an hour (hint: linear scale without a flinch). You get free rabbitmq, mongodb, postgres, redis, https, etc. All of Toyota Europe is run on node on Heroku, and they only use a couple of dynos per country.
Anyway, I'll end this novel with the conclusion I came to after seeing how the sausage is made: Heroku grows with you. It starts free and becomes cheap once you're pulling non-trivial traffic, and it surpasses everything else in terms of app (vs ops) focus. If you'd like to learn more, I'm happy to nerd out.
Cheers,
Hunter
