> That said, has there ever really been an issue with speed as it pertains to markdown translation?

Yes, speed of translation is a big deal. I tried at least 4 Markdown parsers for Python precisely because I needed the right combination of speed and extensibility. When you are constructing a very large static site, a full rebuild can take a long time.

For those wondering, I went with Mistune (http://mistune.readthedocs.org/en/latest/). It is accelerated by Cython.