I used to prefer matte screens. However, since Apple moved to Retina displays, I find I strongly prefer the glossy displays because, with Retina's small pixels, you can see a real difference in text sharpness between glossy and matte, in a way that is not apparent with lower dpi screens.
Plus Apple has significantly improved the glossy coating.
I think that's why Apple mostly dropped the matte option from its MBP's once it introduced the Retina models (there may have been a 13" matte Retina MBP but, if so, that was exceptional).
I did a side-by-side comparison of the matte and glossy ASD's The matte version is superb at killing reflections, and looks great with pics & video (which is probably what it was designed for), but is noticeably less sharp than the glossy version for text.
I suspect the lack of a good glossy option is hurting Samsung's sales of its 5k 27".