Jerry was an acquired taste. I was dragged to a show in 1977 when I was in high school and that was that. A solo during Sugaree tore my heart out. They were still great live (on and off) for the next ten years, but their studio work after Terrapin Station mostly lacked spark and creativity. Drugs. I saw a lot of shows in that ten years, but after that it was mostly just about the scene; the latter shows were often painful. Still, they had their moments. The stuff with Grisman mostly came later, after Jerry's comas (86-87?). Grisman helped him re-learn how to play. The early Grisman/Garcia collaborations with Peter Rowan were awesome. There have been new releases of that Old and In the Way material from the early 70's. Good stuff.
When Jerry was on he was unbelievable. It's hard to explain, but recordings just don't do it justice. I've seen lots of Dead cover bands and post-Dead (Furthur, The Dead, The Other Ones...) bands with guys stepping into Jerry's place, and though some of them were actually more proficient guitarists than Jerry (in part because they weren't on heroin), no one could match Jerry's ability to convey emotion through his guitar and voice. I've seen Jerry sing Morning Dew not knowing if it was sweat or tears rolling down his cheats, and wondering if his voice cracking was because he was crying or something else.
Those who get it get it. Those who don't don't care if they get it or not. The last time I saw Jerry I left the show thinking I never wanted to see the Grateful Dead again. Little did I know that would actually be my last Dead show. That was the summer he died. He was a tortured soul (which made his music often very powerful), and a victim of his own choices. His zest for life was equaled by his sense of tragedy and horror; the combination killed him. To this day, when I'm depressed I'll pick up my guitar and play Black Peter or Wharf Rat or Comes a Time or Stella Blue and tap into the pain. The trick is releasing it rather than feeding it.