Advantages/disadvantages of using the built-in Apache for web development on Mac OS X

What are the advantages and disadvantages of using the built-in Apache for local web development on Mac OS X, specifically 10.6 Snow Leopard?

Instead of using the built-in Apache, I know that options such as MAMP and XAMPP exist. However, for some reason I just haven't wrapped my head around the benefits or potential pitfalls with using the built-in Apache versus using a MAMP/XAMPP-based (or other) solution.

• Is the advantage of a MAMP/XAMPP-based solution simply ease of configuration?
• When not using the built-in Apache are there other benefits besides ease of configuration? For instance, is there a benefit similar to using virtualenv to avoid tainting a pristine Python install?
• If you're only developing static webpages and don't need PHP or MySQL, then why not use the built-in Apache with something like virtualhost-sh or VirtualHostX to ease configuration?

Configuration and Usage Considerations

• I am interested in using virtual hosts in order to simultaneously develop multiple websites
• I use git for version control and have a tendency to store source files in ~/developmentinstead of ~/Sites (this probably isn't material, but thought I'd mention it)

Related Research

• The answers to the SuperUser Question What is the best Apache PHP Setup for a Mac Developer talk about different MAMP, XAMPP, and roll your own so