By reading the "How it works" link provided ont eh page you linked us to.... it sounded like a bunch of non sense to me...
Doing a quick wiki search Gave me the followign link, which seems to suggest that the only "scientists' that support the benefits of ionizing water are the manufacturers of ionizers...
Doing a little more reading on the topic suggests that ionizing water splits water molecules, making alkaline water and acid water... the alkalinic water is the good stuff and the acidic water is the 'bad stuff'. This exceptionally simple usit doesn't seem to have a way to keep the two seperate, therfore they will simply rebind... or so I would think...
It sonuds like a bunch of hoity toity BS to me... but if your the type to spend a few bucks trying out the latest craze, let us know how it works...
The little bit of "reasearcdh" I just did was by no means thorough research, just me, google and 7 minutes...