Tough call... I would probably go with Hartsy though. Giroux could make a monkey a superstar, and he'll give you all the PIMs and Hits you need to go along with above average pts. Ryan is similar in many ways, but he's much less of a sure thing, and he doesn't have a magician holding the wheel.
Also, there were trade rumours last year surrounding Ryan, and I wouldn't be surprised if they came up again this year. I prefer erring on the side of caution, which to me would mean going with Hartsy.