My buddy upgraded from an old Garrett to an AT Pro.
I upgraded from the Ace 350 to a Makro Racer 2.
We both love our machines.
I keep mine away from water and he doesn't have to, but my Racer 2 SMOKES his in the trashy old home sites we hunt. He knows it because he's used both.
Figure out where you're going to do most of your hunting, and what you're mainly hunting for, and make your choice based on that.
I'd wait a little while before buying that Whites unit, simply based on the issues it had. They appear to have resolved them, but I'd still wait before buying.