Which is faster to develop with? If you're using vanilla PHP (no classes / framework) it's probably correct. For a quick and dirty (small) site PEAR does a good job - QuickForm for example.
I used to agree with the fact that PHP was a faster development environment (for small sites), but I don't anymore. I.e. I think ASP.NET is VERY fast to develop in, once you get the hang of it. The web forms framework is very slick to develop in. Especially designing data entry forms is extremely quick. The way it's built also makes code reusability a very painless process. Not to mention Visual Studio.NET which saves you insane amounts of time in a number of ways.