Christan Stocker has posted a finding of the day that he ran across and wanted to share to help out other developers out there:

For okapi we needed to have a function which loads any class with any number of arguments. This is not so easy in PHP as it looks like [...] Since 5.1.3 you can use the reflection extension to do this much nicer.

The difference comes in at about half the time for both side of the examples - with the switch and via reflection.