Jay, I've never heard of Zerto, but the web page you linked to tells us a bit of interesting information.
Firstly, the photo shows a cheese that looks dry and firm (good) but it doesn't really have the yellow tint of other wholesale cheeses. Still, though, it's a lot drier than most supermarket cheese.
but it does not brown as well and is not as elastic as part skim.
Browning is a major defect in mozzarella (that manufacturers go to great lengths to avoid), so I'm not sure why they'd word it this way.
$5.99/lb plus shipping is also a bit painful.
'Low moisture' mozzarella, on the supermarket side, isn't low moisture at all, so, just on the dryness aspect, I think this is worth trying, but, between the color and the references to browning, I'd definitely still keep looking.
I'd also be really careful when ordering mail order cheese, especially during the summer. If it's shipped without refrigeration, forget it.