Would you be in favor of Blizzard creating a Mythic+ Raid Keystone system?
So essentially if the top end guilds clear Mythic difficulty, they get a keystone (which only works for the next week's raid lockout) that they can use on the that would increase boss dmg and health by a percentage and also increase the rewards.
So a mythic boss in ToS currently gives 925+ base loot, but a mythic+ boss could give 935+ base loot and maybe some completely prestigious titles and mounts that would be so rare (because of how difficult a mythic+ boss would be), it would rival that of the Black Resonating Crystal in rarity (the scarab mount from opening the gates of AQ). Not many guilds would be able to complete the full raid and kill KJ on this difficulty.
Basically this would mean nothing to people who don't raid mythic, but it would serve as an extra challenge and progression path, and path to exclusive rewards for the top tier of players on your realm and in the world.
I probably would never see any of these bosses / rewards (unless my guild becomes a little more hardcore and starts doing mythic again), but I wouldn't be opposed to other players and guilds who could pull it off.