The gouge I always heard was that your long term prospects are much better if you return to your original community...eg, VP FO to VP pilot. Otherwise, 2-ish years of NOB DUINST paper plus moving to a new community where nobody knows you means a double whammy for screen potential. At least if you 'come home' you're not an unknown commodity when it comes time for DH, you know the community and mission, etc.
Before they halted transitions in the mid-90's that was where FO to Pilot transitions ended up by default, their original community. For several reasons they changed it when they restarted the program.