Since I have other mango varieties available, I have only picked and ripened one in a paper bag. It did ripen and I would do so if I had no other types available.
My present plans = try to save these on the tree for later unless Bugs, birds, fungus, Humans, etc. etc. etc. start to attack my Keitt Mangos or if they just fall off the tree. If attacked, I will pick & eat if ripe or ripen in paper bags if needed.
Also others have mentioned trying their Keitt mangos for example: kar1ma3 posted in
http://tropicalfruitforum.com/index.php?topic=20918.0 I just had friends visiting from Europe and a few mangoes left: LZ, Maha, Keitt, NDM#3, Pickering, Carrie, Lancetilla, Florigon and .. the best tasting was...