I have an ASP modified Phantom and have had pretty good luck with it stopping rollouts (but not completely). I just bought a Frantom barrel and freak inserts to try to further improve my marker. From what I have read, I think that the Frantom will shoot even straighter and possibly improve efficiency. ASP for the double feeds and together both the freak inserts and ASP for rollouts.
It seems more people are having issues with rollouts with the detents as paint mysteriously shrinks... I'm working on some ideas to stiffen up the detents to cope with tiny balls.