Pricing and more info here:
http://www.hiq-usa.com/At last check, the pH was the same. I have done a water change on it to balance out the nutrient levels.
As I see it, here are the pros:
Allows you to extend the time period between water changes dramatically. It appears to work as advertised for that. This is a benefit to people that hate to do water changes. It keeps the water very clean and pristine. The HOB portion of it is made well and very quiet.
The drawbacks:
It's really meant for large tanks 40 gallons and over. It's unsightly with the two black monolithic reverse flow towers in each corner plus the HOB filter. The assembly of the UGF is a PITA initially but you only have to do it once. The additives are delivered to the tank weekly, meaning that you'd have to purchase the additional suppliments on an ongoing basis. Since there's no way to tweak the individual suppliments, a water change must be performed at some point to restore some sort of equilibrium to the system if any individual nutrient reaches overload (especially in a saltwater setup). The power cost is greater because of the two additional reverse flow powerheads. The reverse flow towers do not break down for cleaning, or at least I can't find a way to open them up.
IMHO where they could be most useful: In berlin style saltwater reef tank setups to support NitrAte reduction.