The best way to see the difference in sky tones, is to make a print on both kinds of paper and then compare.

In my experience, the glossy shows a more continuous even tonal transition from horizon to near-field, whereas the matte paper tends to darken some areas more, showing fewer intermediate tones.

Reflections on paper are only an issue for hand-viewed snapshots. Anything that's framed is going to be far more at the mercy of the glass reflectivity than the paper.

Cheers