Careful Agent Orange, I think Lucas is not talking about pole pieces but about covers. Those do make more difference than the pieces.
It is hard to say if any PU sounds better, it really is a matter of preference and guitar / amp. Of course something like a WP or Crawler is a bit more on the danger side when it comes to being covered, where as the RY and EMerald bridge handle it much easier. Open coil really provides more cut and treble, but the bit of rolloff you get from the cover is very nice and musical and sublte enough to be used to great effect (which is why it is more common on the neck than the bridge).
YouŽll have to look at the guitar, amp and what you want really.