It could well be, certainly up there with his great ballads like Comes A Time, Brokedown Palace and Stella Blue. I don't think there was ever a song that fitted Jerry better...he was quoted as saying about Mission - "sometimes Hunter acually writes me, since he knows me so well". Certainly it was interesting how he kept it for his solo Bands. It's one of those where the vocals need to be 'on' for it have full effect.
But musically what Jerry did with it is so brilliant. The revolving solo he played, how it slowly built up and then peaked and then slipped down stream again enjoying the view...full of high notes that really reach down deep. pure class.
JGB - March 18 1978 is a perfect example, crisp guitar work.