Hi Bev,
I'm not sure in my case nostalgia is in play. . . . I actually hear more in the music than I did before and I think not only does this tickle me but it is intriguing me to keep exploring it. For example: one thing that netted me into this recent spree is noticing a distinct similarity in playing between Kreutzman and DeJohnette. No one influencing anyone, but a similar way of connecting bass drum, tom and cymbals in patterns that both mater drummers have going on. . . . Also, as you mentioned, the sort of interaction of the guitarists with Lesh in these jams reminds me of jazz interactions that I hadn't quite absorbed and identified the first time I was a "Deadhead" and do latch right on to now. . . . Nothing about the era and time really holds nostalgic appeal for me. I'm so glad I'm not living the life I did then, alienated preacher's son in a very small town in Ohio! Anyway, I'm enjoying a lot of the music this time around. . . even those cowboy tunes, which like you I sort of skipped over before.
You guys are making me realize I need to get Two from the Vault, the five cd live set, etc. . . ARGH!