AG is actually brighter than the glossy, just that the colors on the glossy pop more. At night, when lights are off and dim.... glare and gloss is not an issue on the glossy display as it is minimized...
colorwise... it will look much more vibrant since well... its glossy. AG will look good, but it won't pop as much as glossy. At night with low light.... the only disadvantage of glare, is removed. Having a light source behind where I sit... turned on sometimes... the reflection is apparent.
Why do people say that the Glossy is fine at night? On any dark background the lit up keys get reflected in the screen I know as I had one and was really annoying to see keys reflected.
I think Glossy vs Matte is really a question of wether or not you are bothered by reflections. If you are not than the glossy is easier to clean, less likely to scratch, a bit more saturated, a bit better contrast, and a bit sharper. On the other hand if you are bothered than stay away from glossy as the apple glass is worse than any other reflective glossy screen you ever tried.