I did some more checking and it does say it can be used w/ gravity but you need 4' elevation. Anyway, are you getting a lot of hop flavor and aroma with it? As opposed to whirlpool/hot stand hopping, any difference?
More so of an aroma thing than flavor. I did a side by side of an IPA where I ran the first 5 gallons of wort through the rocket and the second 5 gallons I just whirlpooled and hot stand hopped as normal. I did get more aroma from the rocket, flavor impact I found to be minimal. It definitely gave that big whiff of hops, but honestly I don't use it in very often, only in big IPA's where I want a ton of hop aroma, and I dont brew those all that often. If you're the kind of guy who likes a lot of hop aromatics in several styles of beer and do those styles often I'd recommend it. Otherwise you can get very similar results with cold steep, hot stand, whirlpooling.
The other thing to consider for that I like more than using on brew day is using it as a randall. I actually prefer it for that use. Ive been searching for ways to use it and another thing im considering is whirlpooling cooled wort through it with some whole coffee beans or wood chips in there.