Fans probably want the extended versions, but I bet people will buy it twice. Back in the laserdisc days, I know people who bought Episode 4 a total of 5 times.
I enjoy the movie for what it is, but I personally am not a fanatic. The standard cuts already border on being too long, especially RoTK.
That movie built to a climax and then resolved into an ending. And then another ending. They ended that film six times for another 40 minutes. It got old to me. In the screenwriting classes I have audited, they taught that you hit the climax and then get out as quickly as possible. Always within 5-10 minutes. RoTK climaxed when Frodo threw the ring.