It's a weekly news show that focuses on tech (mainly Apple). They do a good job with technical details and talking through tech product decisions (why did Apple/Google/FB do X? What are its merits?). People have sort of polarized opinions about each of the 3 hosts, but IMO they each have their moments.
To me, one of the powerful things of ATP is that it’s one of those cases where the sum is more than the parts. The hosts complement each other very well.
I also like that, although it’s an Apple-centered podcast, they are willing to take a critical stance towards Apple. I once listened to one of the other major Apple-related podcasts (not Gruber) and the level of fanboyism was cringeworthy.