Yes, Elvis was indeed a perfectionist in the recording studio!
To quote Scotty Moore: "You could stick a fork into it, when he was through recording a song!"
He wasn't satisfied until the song was "right" in his mind.
I guess he would NOT have liked that all the alternate takes now eventually is being released.
But it's interesting for us fans to see how he and his bandmates worked in the studio, that's for sure!