I would not say that a higher ORP means higher quality water. ORP can be raised by dosing bleach, for example. This article covers ORP:
http://www.reefkeeping.com/issues/20...ture/index.php
There are examples of perfectly healthy tanks with ORP below 300.
As for why this product is raising ORP, that's very difficult to say without knowing what's in it. The best case might be that it is help to remove organic compounds from the water column by feeding bacteria that are then skimmed out of the water. That process might be useful for some corals. The product might have an oxidizing agent, as well, though.