Make sure you buy the fully loaded one. I don't think the base models are that comfortable. It sounds that you've never tried one. Make sure you test them out. By "them" I mean the three different sizes; A, B and C (small to large sized).
They are great chairs. I didn't think much of them, besides the look and style, but when I started work with my current job, I realized how comfortable they are. Sitting for long periods of time doesn't become uncomfortable. I ended up purchasing two for my home; one for my wife and self.
To add: I'd stay away from the leather arm rests. Those could become cracked and torn. If you set the height of them equal to the height of the bottom of your desk and the two surfaces rub, then the arms may damage. The rubbery regular arms are more durable. They don't make the chair look bad at all. Good luck!