If you get the Etha now, you can save that money for other things, like paint/field fees... or non-paintball-related stuff.
But if you wait: between the Etek4 and the FX, go with the Etek4; between the Etek4 and the Reflex, that's personal preference. I don't know if you prefer poppits or spoolies.
I can't really decide whether you should wait or not. It's your money.