I agree that you need to go see them in person.
I have always had the matte finish from my Powerbooks, so I went with what I was comfortable with on my MBP. My wife has a Macbook with a glossy screen, and I think it would be too glossy for me. I don't use it that often though, so maybe you do get used to it.
It seems like the glossy finish it supposed to provide increased contrast and be better for Photographs. For Graphic Design work, you might want the matte, for less reflections.
In the end though, I think it all comes down to personal preference...