From a Miranda stan POV, it is considered her weakest because it's her least-involved album. She's somewhat phoning it in. Also, FTR is the first album Miranda's made with "hits" as her main focus, so we get some weaker songs like "Fastest Girl" and "Baggage Claim" on the album which only serve the purpose of being singles. It's still a great album overall, which is a testament to Miranda her power.
I'm glad you've extended the deadline! It's been midterms week so I've had no chance to give my final listens to Carrie and Faith, but I'll be able to do that today after class