First off, I self-studied the AP, so I suppose you can take this with a grain of salt, but here was my experience:
I had Barron's from the beginning, and I must say, I absolutely hated it... I used it up until the week before the AP, and I'm pretty sure I didn't learn anything. xD
I switched to Princeton Review, and it was okay. Decent explanations and what not, but not phenomenal...
Finally, it's that Friday before the Monday AP, and I'm freaking out because I know I'm going to fail it.. Barron's didn't help at all, and
PR wasn't doing much for me either... (Although maybe it's good to just complement the class)
So like I said, it's that Friday, and my 5 steps to a 5 book came in after waiting 48438 weeks. (Bought it off of eBay, lmao) Anyway, I crammed 5 steps to a 5, and I feel like I definitely learned a lot more compared to Barron's and
PR.
In the end, I only pulled a 3, but I'm pretty confident if that book had come in even a week before, I could've pulled a 5.
Like I said though, I self-studied, so take my experience with a grain of salt.