Seems like a lot of people don't like the namespaces changes. I actually really like this! I suppose it's cumbersome even if you're building a project where you have full control. Then again - come on, we're talking about search&replace for 10 minutes here. And in more complex projects, you should have had a flexible function to handle icons anyways.
Why I really, really like it: If you're building something in a namespace polluted environment (say, a component for a popular CMS), this is a damn god-send.
I was on the fence before, from now on, it's fontawesome all the way for all my projects. They've done an amazing job so far and I'm looking forward to what they will do next.