At the end of the day, a slightly damp (with water) microfiber to remove any stuck dust / smudges, and then a fine microfiber (like the one that comes with the laptop/screen) to "polish" the screen or remove any faint streaks from the water, I think is the best long term solution.
1. It doesn't introduce any chemicals (regardless of if they are advertised to be ok for your monitor).
2. It doesn't involve a recurring cost (other than the initial towels), like refills of the spray / solution.
I have a glossy retina MBP, and this works like a charm each time.