Markdown is a fantastic language for quickly putting together a blog post or some content for a website. Personally I use it a lot. In fact, I used it to write this article.
The main drawback of Markdown is that you are confined to a fairly limited subset of what is available in HTML. Most notably, you cannot define the majority of element attributes in Markdown alone. That said, Markdown wasn’t designed to be a replacement for HTML. It aims to make it simpler for web writers to create content. A goal that I think it achieves very well. The ability to mix-in HTML also allows you to circumvent the issue of being occasionally limited by the native Markdown syntax.
If you haven’t tried using Markdown before I encourage you to check it out. If you regularly write content for the web you could find that it makes your writing experience much more enjoyable.