The Rockhopper is really hard to sell next to Kona's lineup in that same price range. Kona's tend to be spec'd out very well for their price, with the good stuff where you need it and lesser stuff where you don't. Thing is, their geometry absolutely sucks for XC riding, even on their XC bikes. I guess its kind of a wash. I'm not really thrilled with the Rockhoppers since they use cheap stems, bars, and other components through the whole line, but the geometry is better. Giant has ok geometry with really nice components, but usually really lousy forks, though lately I've been steering more customers that way if they aren't looking for something as aggressive as the Kona.
commuter turned bike mechanic turned commuter (also a Velocity USA employee, but this is my personal account)