from what i gather from my researching this it allows you to connect to more towers. Sprint gives priority to its post payed customers on the towers and im only assuming that this is controlled in part by the PRL so if you load the sprint prl you would in turn be on a sprint post payed signal. I was able to have the phone see the airave "tower" when i had a sprint PRL on the phone but it would not allow me to make calls with it
I can confirm this to be true because I use to have crappy reception on the first floor of my house. But, since I changed my PRL to a Sprint post-paid PRL, my reception rarely goes below 3 bars on the first floor and I have full signal everywhere else.
