Just tried a beer put through one of these over the weekend at Bootlegger's Brewery here in OC. They were using centennial and cascades, with an APA going through it... pretty good! Not as intense as I thought it would be, but I don't know how long it had been in use. The sample that I had poured normally, and was carbonated just fine. I can see how it would be pretty challenging to get it to be balanced just right though.
I didn't see their "hopinator" as they called it, but I heard the guy say that they basically had a hop bag in a water filter housing. The only other thing you would need to add is some sort of tube inside it that runs to the bottom, since both of the ports on those filters are on the top.