Scroll toward the bottom of the page. Side by side comparison of all 4.
https://www.holley.com/blog/post/how_to_choose_the_right_holley_stand-alone_efi_system/
Wish I would've used them when I replaced my WH. My house only has copper on the stub outs. The rest is CPVC or the like. When I put my WH in I must've cracked one of the joints behind the wall for it to just barely drip. Took until last year for the water to be seen. Nice moldy mess behind...
The fact the Terminator isn't seal would worry me. Dust can cause damage just like water. The first digit in an IP rating is protection from foreign solid objects. The highest rating, 6, is protection against dust (tight).