When Elvis was eager to work and was up for a challenge, there was really no stopping him. I agree that new people brought out the best in him in normal circumstances. My only concerns at this point is his drug dependence and the haze that he was in. I think everyone would agree at this point that Elvis should have focused 100% on kicking the drugs. Without doing that, he was at the mercy of the sycophants, controllers, and the drug effects. Elvis had the talent and regardless of producers, he had the ability to deliver. It just seems that Jarvis at this point had the advantage of knowing Elvis well enough at this state in his life to avoid the land mines and get something out of him.