Even if Nolan took a step back to focus on Westworld, Denise The, Greg Plageman, Lucas O'Connor, Amanda Segel, and Erik Mountain were very dedicated... Let's take a look at some of the great episodes:
Season 4
Panopticon
Prophets
The Devil You Know
The Cold War
If-Then-Else
Control-Alt-Delete
MIA
Search and Destroy
Terra Incognita
Asylum
YHWH
Season 5
BSOD
SNAFU
6,741
QSO
Sotto Voce
The Day the World Went Away
.exe
return 0
Okay, this is my opinion, but my list of great episodes goes like this. Unsurprisingly they're a bit different lists from yours. I didn't enjoy that much of season 4, and while Season 5 had some real bangs, I didn't care much for the ending.
Season 4:
Nautilus - loved the idea of a Samaritan recruitment drive
Brotherhood - where Reese and Fusco protect those kids (really recaptured what made the show great in season 1 and 2).
Pretenders - IMO best episode of the season, funny, action packed and with 2 brilliantly written stories side-by-side.
The Devil you Know - a great episode which really showcased what has made Elias such a compelling character throughout the show (but they never really followed it up effectively).
The Cold War - a good episode (we agree on that) for Greer's backstory although as I've mentioned before the restraining of Shaw didn't work for me.
If-Then-Else - the multiple scenarios were terrific (sort of a super "sliding doors" episode). Again, I thought it would have been a great ending for Shaw, but that's just me and one other person. Still, a great episode.
I struggled with Terra Incognita, as it was great to see Carter again - but John seems to have really lost his edge.
YHWH - some great moments, in terms of Finch communicating with the machine directly, but really did we need to go through 4 seasons to get to this point. I guess my issue is that I feel like the whole Samaritan storyline was only worth 1 season at most, and this episode should have been a mid-season finale rather than a season finale.
Season 5:
6,471 While I'm not as big a Shaw fan as everyone else posting on this thread, she really shone in this one (and while I think she should have died in If then else, I have to admit that this was a damn good follow up).
Sotto Voce : loved the Elias/Finch as a kind of weird Holmes Watson team, and of course the "Die Hard" aspect of the police station hold out.
Syncdoche - hey, it was neat to see that the machine had another team something I always hoped the writers would explore - but then where were they when the **** went down in the final episode ?
As for the finale, there were some good Reese/Finch moments (and I liked the Vonnegut reference, Ice-9). Still don't think that John needed to die, what was the point of developing a love interest or all that character growth ?
I mean, he was prepared to sacrifice himself for Harold, from quite early on in season 1 - so he didn't need to prove it here.
All in all, I felt season 4 had some good episodes and great moments, but season 5 was sort of a rushed mishmash.
Guess it works for some folks, but didn't work for me.
All the negative opinions you mentioned in season 4 and 5 are some of the reasons I find these two seasons a disappointment. I think Nolan being focusing on Westworld made him "somehow" neglect POI, I feel like after season 3 he and his team didn't take the show seriously anymore. They didn't put enough effort and dedication to it.
I suspect that Nolan's absence contributed to changes in the show. Certainly when I look at the writing credits over the course of POI, my favorite episodes were all written by Jonah Nolan (in particular the "Devil's Share" ) it was Nolan who introduced Shaw in "Relevance" and you can certainly see a trend of his diminishing involvement as the show went on.
I honestly don't know if it was a question of the team not taking the show seriously - but perhaps they had a different vision for it, compared to its creator. I feel like they wanted to explore other ideas, and moved away from the core concept that Nolan established (and which made the show compelling from episode 1).
In a similar way, I loved the first 5 seasons of Supernatural (which were under the creator, Eric Kripke) but after that feel the show has been entertaining but lost a compelling overall direction (compared to the Apocalypse in season 5, but I guess after you avert the Apocalypse its hard to go anywhere else ). But that's just me, plenty of folks love the show, long it enough to keep it going 7 seasons after Kripke's departure.
Cheers.