On his MontanaProgrammer.com blog Chris Roane looks at the value of a PHP programmer and what you might look for when considering which developers could make the most difference.
Over the years I have come across PHP programmers from different backgrounds. I've seen some do very well, and others fall flat on their faces. One unique element about PHP programmers is that they vary in quality more than most other programming professions.
He mentions traits to consider like speed of coding, reliability, experience, humility and be able to accurately estimate time to finish work. He give the example of three different developers - each with their own skills and experience levels and asks which of these might be the best. The trick is, "best" is very subjective to the needs of the company that wants the code written.