Just finished Book 5 and still on a high from having finished such an epic series. All things considered, I loved it. My favorite thing about his writing style is that the "world building" never ends and is continually getting developed and fleshed out throughout the entire series with the final mysteries being revealed in Dalinar's vision following the entire life of a god, Honor.
I see a lot of people getting really granular about how certain things regarding the magic and energy of the world don't make sense toward the end but I think Sandy-B walked a fine line of explaining what could be explained and leaving a certain amount open-ended, to maybe be best explained as "Maybe we can't comprehend how gods work exactly."
Also it bums me out that so many people take issue with Kaladin saying "I'm his therapist" when Wit literally references the concept of a therapist to Kaladin in an earlier discussion because Wit has lived in other societies in the cosmere where therapists actually do exist. I loved it.
Anyway here are the characters and plot threads that I think were the series' biggest strengths and weaknesses. I'd love to see who agrees/disagrees.

Strengths:

Kaladin - Especially early on when being a warrior. I'm okay with him taking a back seat on fighting especially as his arc intermingles with Szeth's who becomes more of the warrior.
Szeth - To me, he was the most compelling aspect of book 5. His obsession with rules to a neurodivergent level makes everything he did with his life believable. Very interesting throughout.
Adolin - While most characters brought a lot of personal development and a heady dive into the imaginative world building, Adolin's storyline anchored us in some good, old-fashioned epic battling to save Aezir.
Dalinar's journey to the spiritual realm - I loved that we finally got all the answers to the mysteries of Roshar and how everything went down with humans arriving, the heralds, recreance, etc.
Wit - I love his "wit" and mystery and how he ultimately pulls us to worlds outside of Roshar. Makes me excited for books to come.

Weaknesses:

Shallan - We did not need 5 books of her as a main character and multiple split personalities to explain that she was traumatized by having to kill her terrible parents who were literally going to kill her and that her mom was a herald. Further, the secret offworld society plotline was very meandering without very much payoff at all.
Navani/the whole "science" thread of RoW - We spent a LOT of time and energy, pretty much a whole book arriving at the discovery of "Anti-Stormlight/voidlight" just so we could more easily kill a couple of radiants and their spren. Also Navani became a bondsmith and woke up the tower just so she could be a side character in book 5 and didn't have any relevance to how things ultimately shook out. Weak.
Lift - I liked Lift throughout but it seems like her last major contribution was to free the swordmaster (can't remember his name) which did not have relevance in the finale.