Well, as someone who is very much familier with the Arrow 2 and also with the basic changes in the Arrow 3 system, I can say that I would go for the Arrow.
As someone here already said, this is the only system in the world that was tested properly and was prooved damn good.
In December 2005 I think was the last test of the Arrow 2 againts a ballistic missiles coming from Iran, a very high speed missiles ( Mach 8.5 if I remember correctly ) that changed it course during the test few times, and the Arrow didn't had any problem calculating the new course each time and intrecepted the missile with 100% success.
Never, in any test, an ABM system have accomplished such thing.
I wont say that the Arrow doesn't have bad sides, like the high cost of each missile that it is a problem for country such as Israel, that needs it the most but doesn't have the budget for it.
Also, I think that the Arrow mobility system ( an Arrow battery mounted on vehicle ) is not very good.
And the reason is very simple, that in a country like Israel it doesn't matter where you put the battery, in a speed of Mach 9.5 the missile will work the same from anywhere.
I know there's 1 mobile Arrow battery in the Israeli south, but I do not know how does it work, but I heared its not anything like the S-300 or S-400..