I have discussed with MOOG a while back and they confirmed that the individual ball joint is more "heavy duty" and a better ball joint. but that does involve drilling out your old ones...
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)