UTStarcom PPC-6700 / XV-6700 / HTC Apache

My understanding of the benefits of wireless sync is that it will monitor a continuously running PC and push email out to the phone as it comes in. Is that a correct assessment?

In the setup they talk about setting it up for POP access. I already have Yahoo POP access working (even though it seems a little flakey). Why would I use it for wireless sync too?

thanks