If its outside, in direct sunlight, and your going to be doing strenuous work (Photo editing, etc) - you will need matte.
Personally, I love the new glossy screens - I just think they should be a B.T.O, not standard on the MacBook.
For what I need, I would get a glossy - they're sharper, brighter, and just look cool as 🙂.
Hope that sort of helps.. 😱