I prefer the Glossy displays. I've had both a Matte and Glossy MBP and I've stuck with the Glossy. Blacks are very very black and colours are more saturated and the display looks a little bit sharper to my eyes. However, the Matte displays just do not reflect light at all, and as such are perfect for places where you might have a lot of bright light sources shining onto the display.
I actually find the Glossy very usuable, even in places I thought the gloss would make it difficult to use. Your call of course, but for a portable, I'd go for glossy.