OK my assumptions were correct, 23A is a good seat, it reclines and you can use 21A as your under-seat storage. Although having to unbuckle your seat belt to get your stuff is a little bit of a pain. Also, your tray is in your armrest, and if it's one of those seats on which the armrest doesn't go up. There is no power outlet between 23A and 23B, but there is one between 23B and 23C.
Row 21 does not recline. Row 22 might recline, but I'm not sure. 21 has a lot of legroom though. 23, has normal E+ leg room although obviously, A and F have tons of leg room. Not sure why 22 is not E+, looked like there was a decent pitch, but maybe not.