I listen to most of these podcasts on a regular basis. Each has their plusses and minuses. Here are some my current impressions and grades (I'm a tough grader):
Celtics Beat used to be my favorite, but Adam Kaufman has neglected it, and the producer who sometimes fills is long winded and doesn't let his guests speak. B -
Anything is Poddable: Jay King is kind of lazy, but has pretty astute observations. The host, Sam Jam, is pretty immature and annoying, and just lacks knowledge. C +
Celtics Talk: Forsberg and Draper have decent banter. Forsberg is very knowledgeable, and tends to talk too much Kyle plays devils advocate to good effect. Sherod was part of the team until let go recently and frankly have not really missed a beat. Solid B.
CelticsBlog: This is very hit or miss. The British guy who usually leads started off well, but really was dreadful when he did exit interviews after the season with other journalists and asked just the same awful questions. The two brothers who substitute host are quite knowledgeable, and maybe a bit critical, which is good. C +
Locked On Celtics: I really like John Karalis as a journalist, a good writer. But his podcast is difficult to listen to. He doesn't seem prepared, and just lacks radio presence. He could really use a good partner. I've stopped listening to him. D
Gino Time: Tom Westerholm and Nicole Yang co-host. I think this is actually pretty good. It is well organized. Westerholm knows his stuff, especially concerning the draft. Yang is clueless about the draft (self-admittedly) but does know the team and players quite well as a beat reporter. She tends to be less a fan of the Celtics than I would want to hear, but objective journalism is a good thing. B +
Celtics Reddit: This was really good before the pandemic, but has stopped running on a regular basis. Led by an Aussie, and QiWi and a Yank. B