I'm generally not a huge fan of reverse cambered boards, but I've owned a 154 Joystick for the past 3 years and love it. I don't ride it all the time, I have a Capita that I use as my main board at Northstar, but when it snows a bit or I ride a bigger mountain, I really enjoy the Joystick. The one thing I hate about reverse camber boards is that they don't have the edge grip that cambered boards do (duh), but the Joystick is a stiff enough board that when you do put it on an edge, or are going fast, I don't feel that I am going to wash out on it. It's definitely doesn't hold an edge compared to some of the other boards in my quiver, but that is to be expected. I just change my riding style to fit the board. I really only ride it when it snows a bit at Northstar (not enough to bring out a Malolo), when I'm riding a bigger mountain but still want something playful, or when I do want to ride a V Rocker deck.
I do enjoy it in the park. Like I said, it's stiff enough to handle the bigger jumps and stuff, where more flexible RC boards will fold and wash out on you if you don't land on the bolts, but the V rocker still makes it fairly easy to play around with it/do flatland tricks and press on rails/boxes.
Overall, I really enjoy it, and it'll be in my quiver for a while. I definitely recommend it. They pulled the plug on the Joystick last year, so there will not be any new models coming out, so pick one up if you can. I sold my 2010 and bought a 2012 solely because of the graphic from last year. One of the best graphics to come out in a while IMO.