[RyanPorter]

You learn "good" habits from using cloud systems. You shouldn't be spending your time manually configuring your machines, you should be using DevOps to use source code to configure your machines. And building your own hardware is a great way to save money but you're still making capital expenditures when you could shift those expenses to operational expenditures, which is really the biggest benefit of cloud computing.

The systems all scale differently, depending on how their abstraction works. With Heroku yes, it's very easy to throttle up to more "dynos". They deal with the details for you. With Engine Yard, you have more control and so it's a little more involved because you instantiate new app server instances but it's still just as easy.

And using cloud systems also actually improves your architecture too. Instead of using local storage, you'll have to use a CDN like S3/CloudFront, which really is what you should be doing in the first place.