I have a couple of friends flying UA CLE-SFO-CLE in October. He's 6/4", she's 5'8". They haven't flown in years, so want some advice on seat selection and other aspects of the flight. They're willing to shell out for Economy Plus. I haven't flown UA Y in a very long time, so would welcome any advice.

1. Basically, should I advise them to go for regular economoy plus or exit row? (And does the exit row have greater legroom than economy plus?)

2. And if they go with the exit row, am I correct in assuming that row 21 is better than row 20, since 20 doesn't recline?

It looks like outbound they're on a 737 Max 9 and a 737 Max 8 on the return, though I realize both could change. I also realize that Seatguru isn't always reliable, but FWIW it indicates that certain window seats in 21 are less desirable due to small armrest and/or limited recline. (I'm not yet sure whether they'd prefer aisle or window, along with the middle seat.)

Thanks for any advice.