It depends on the track - it depends on the album.
"Two Heads" -- Q. - How tight /Together is that ?? A. Very !!
"Embryonic journey" - ok a solo by Jorma---isn't that the definition of
neat 'n' sweet?
However, some of their Live Material does 'meander' - on some of the
tracks on some of the time....If you had happened to be 'there at the gig' -you would have probably eally ,really enjoyed it....but listening to it at home in a different ambiance ( remember...."Set & Setting ", Yes ? ) - is a different vibe.
It's been the case 'back in the day' where Gigs by Groups didn't have to/were not expected to....reproduce 'note-for-note' their tunes from their L.P's. It is more likely-than less likely, - that a band does nowadays. (This is probably more boring for the musicians -and for some of the audience-whilst others in the audience would appreciate hearing different/extended versions of some of the songs...
As far as the G.D. being a 'Jam' band....this is a rather simplistic musical
label....the Dead could jam/extend a decent tune and explore its moods
and colours withever way they lead down whatever path kinda opened -
- up to them....Live. In L.P. record-mode, listen to 'American Beauty' and
' Workingman's Dead' & you will find short, sweet, crisp tunes a'plenty...
Silly to put 'Stick - On' labels onto the Best Two Groups the U.S.A. has
given the World, in my opinion.