Having said that the 18th was a bit rough around the edges, I should add that the Dark Star is very interesting. I believe this is about the time Jerry decided he was pretty much done with that tune. The same goes for St. Stephen; "the reason we didn't do St. Stephen for 20 years was that Garcia hated the bridge," Weir told his Other Ones bandmates in a 1998 rehearsal (Prompting Hornsby to reply "He's just a guy who drank too many milkshakes, ate too many burgers. Fuck him."). St Stephen disappeared for a while after Halloween 71. It came back for three years, 76-79, and three performances in '83 were the last of it.
Mickey famously left the band after the first night after a long bout of depression and a near-total mental breakdown brought on by his father running off with about $150,000 of GD money. I don't know just how it went down, but Weir told the crowd he was under the weather (three times). His departure did not adversely affect the performances though. It's almost as if having one less drummer simplified everything a bit, leaving more room, taking a cog out of the machinery, as it were.
In my opinion, the 19th and 20th are the best nights of the run, but maybe I'm getting jaded; the repertoire is a bit slim, with nightly repeats of Bertha, Playin, Greatest>Johnny B. Goode, Loser, Truckin' and Casey Jones, and five performances of Sugar Mags, Bird Song, Wharf Rat, and Me & My Uncle. There are also a lot of tuning breaks, sometimes between each tune, prompting a lot of "Dark Star!" and "St. Stephen!" from the crowd. Weir seemed to have the most trouble, notably aborting Ripple on the 21st.
There are some really standout tunes sprinkled throughout. The Wharf Rat from the 21st is very nice. They slowed it down a bit and got the form down pat. The vocal arrangements are a bit tighter together than they would become later, but there's always a nice long "liiiiiiiiife." Favorite Bertha on the 23rd, favorite Uncle John's closing on the 21st (so far, I have not yet heard the last night)
The Pigpen tunes are, by and large, fantastic: Smokestack, killer Good Lovin,' Hard To Handle, Easy Wind is in its prime; my favorite is on the 21st, even though Pig blew the lyrics like you wouldn't believe. His raps during the extended Good Lovin' jams are tons of fun. Aside from the traditional "Pigpen fix-up" where he tells all the guys to get their hands out of their pockets and go harass girls, there are some longer stories and improvs. On the other hand, his keyboard parts can be nice, or awful; check out the Candyman from the 18th for some drunken key-jabbing.
Weir is real impressive throughout. He takes extended solos in Easy Wind and during the China>Rider transition that are some of my favorite passages of this period. But if you pay attention, particularly during Bird Song, he's got some really tasty licks in there.
Phil is particularly prominent on Morning Dew, with (I believe) that great big Alembic-tweaked Starfire with all the knobs and do-dads. He was also singing quite a lot back then, mostly the high-register stuff that would wreck his voice later.
Finally, these were the famous ESP shows: at 11:30 every night, during the second set, slides would be projected behind the band enjoining the audience to try to telepathically beam images to a patient about 50 miles away. The results, published in The American Journal of Psychosomatic Dentistry (!) and Medicine, were "statistically insignificant." Oh well.
I will post one more discussion of the Port Chester run in a day or two.