even if they are run independently, there will be no ambition to reduce rake or increase rakeback in order for one site to gain more customers than the other. for that you need true competition. they'll also need to try and balance player pools so that both sites are big and have plenty of players on at all times, which might mean they delay releasing innovations or change schedules to encourage some players to switch to the other site
i didn't have much on ftp, only low 3 figs, altho i did prefer their software and they did have some epic tournaments, but that was largely destroyed with multi entry