I agree. I'm not a Deadhead, but I've played in bands with Deadheads, so I've ended up playing some of their tracks over the years and I'm now in a short-term Dead cover band. I love playing their stuff largely because it's so fun to develop my own parts while staying faithful to the tracks. I do copy some of Phil's parts, like "Shakedown Street," but I'm usually doing my own thing that's informed by Phil's approach. It's a blast, and my Deadhead bandmates seem totally cool with it.
Some of it feels natural, I think because from 2008 through 2018 I played in an original band whose leader/songwriter/rhythm guitarist and lead guitarist were both hardcore Deadheads. For warmups, I jammed on several Dead songs, sometimes without even realizing it, and now that I'm learning more Dead tracks, I'm seeing how much that songwriter was influenced by the Dead. As a result, some of the approaches I developed for those tracks have been helpful with actual Dead songs.
As far as I know Phil didn't play J-basses much, but I think they're great for the material. I like the treble punch and definition for the melodic parts, and the heavy lows when called for. I've been using a Sandberg California TT-5 Superlight in the Dead cover band, and it's been great IMO. (Heck, Oteil was playing a Sandberg six on the Dead & Co. tour, so I can't be
too far off!

)