It was a great movie imo. It had a little bit of everything and the ending definitely got me choked up. I just wish the original cast (i.e. Buzz, Jessie, the Potato Heads, Rex, Slinky, Hamm, etc) had more significant roles given what they've all established in the prior 3 films.
I didn't like how Bonnie neglected a lot of Andy's toys though given how Andy poured his heart out to Bonnie about how special they all were to him (esp. Woody) and that he trusts her to take good care of them, and in this one she ended up losing Woody and on multiple occasions, nearly lost the whole gang. I know she's like 5 years old, but still, the way she treated Woody and the squad in TY4 kinda put a damper on that awesome TY3 ending imo at least.
If I had to rank the four movies I'd probably say:
3 > 2 > 1 > 4
Thing is, all of them were great movies which made it hard for me to rank, but I do believe this one was the "weakest" of the four, which isn't a knock on TY4 at all, it just shows how successful this franchise is overall.