I use DLL's coded with Visual Basic which does all the MySQL database related things. ASP only creates/renders the web-site. It's fast because VB is not script language like PHP and ASP are. I think the best part is that you can debug both ASP and VB when coding with Visual Studio 6.0/.NET so development is fast. Sometimes it might be hard to resolve errors when you can't debug your code (I haven't heard that you can debug PHP. I might be wrong.....).
I use both ASP/SQL Server and PHP/MySQL, both at work and for "casual coding"
I've recently undertaken a feasibility study testing the viability of moving our large (many Gb) SQL Server database over to MySQL. In summary, the results (based on lots of custom profiling) were:
ASP + MS-SQL = slowest
ASP + MyODBC + MySQL = fast
PHP + MySQL = fastest (by a factor of nearly 40% at times)
This is for a database that is very read-intensive with a 0.5 Gb buffer given over to InnoDB.
Adding the ODBC does slow things down a little. The fact that PHP has a native library to tie into MySQL helps a great.
I prefer PHP, but then I come from a C/C++ background. As for not needing to debug PHP - no offence but that's a crock. Every professionally written application needs testing and debugging, no matter how "l33t" the language or programmer.