ORAC,
Well, they indeed can hit most of the flying pieces of metal tubes (that Hamas rockets are made from), but not all, BTW. During one of my visits to Israel I even watched a couple of successful interceptions (explosions in the air) with a local friend of mine (wives preferred to stay deep inside the house). But is it a scenario envisioned for that remote archipelago?
IMHO, a good alternative (from the battle management stand-point) would be a kind of SSDS (ship self-defense system) installed on (US) air carriers, but a bit more distributed across the shoreline.