Tournament blue reflects light better than green. It will make your pool room brighter and livelier. All green is drab. I definitely prefer to play on the blue for the reflective quality, seems easier on the eyes for extended playing time.
I personally as a player do not care what color the field of war is. As a tournament director, the greatest discontent from potential players was received when trying to play on red cloth, with required red chalk.
Incredible amounts of whining, albeit from players that had never played a single game on the tables.
Being a bit of a traditionalist I have Green 860 and Centennials at home on my GC. I do not mind playing on the blue. My observation in my home pool room that switched from green to blue. The Blue does not WEAR as well as the Green. the blue seems to show everything faster than the green did. dirt, stains, ball marks (break lines, lines on the rails near the corners, ball divots from jump shots, etc.). If you are looking for a traditional classic look and one that lasts longer stick with the green. On a side note, I had my table mechanic turn my GCII into a black table when he re-furbished for install. the green looks really nice against the black.