Personally I like the flexibility you get when using PHP. However, ASP.net is quite fast to write a quick application in. It is used by a lot of large companies for web dev as well. Page layout can be done using point and click in Visual Studio though you can directly access the HTML markup and use templates, css etc.
With no adjustments to the languages (besides turning on page caching in asp.net) the benchmarks I have seen point to ASP.net being slightly to moderately faster.
The reason for this is that ASP.net is compiled whereas PHP is an interpreted language.
