There's a reason why smart people uses PHP instead of Rails: Most notably it's proven to scale (Yahoo, Facebook). I have personally tried Rails and love it to bits. But the performance issue is not worth it. In the end, i wrote my own stripped down Rails-like framework in PHP in 1 week and migrated the app in a few days. Performance boost was very noticeable. (Avg page loading time dropped from 1.5 secs to 0.3s)
And to those anti-PHP fascists, yes it's possible to write neat PHP code. There is no scattered SQL in my app since i follow Rails' MVC structure. And since I code "functionally" and don't use PHP OO features, so its half-baked object system doesn't bother me.
I don't mean pure functional. I mean i use lots of functions instead of object methods. I don't like mixing data with functions.