Which modchip with PAl 39004 ?

[BG]

The Main difference between the mod chips is what version PS2's each of them work in....
You have to remember.... ALL of the "direct boot" mod chips are nothing more than "clones" of the Messiah... They are all built off of the Messiah technology...
There are slight differences in the boot procedures for each mod chip....

The question is : if it works, isn't one modchip as good as another ?

Basically yes.... Its a matter of "brand"
Some people like to stay with a "better brand" (not necessarily a better product)

So the choice is yours....