Seatguru hasn’t been updated in many years and is no longer reliable. Use Aerolopa.

Row 18 has extra legroom on some seats on one side as the loo is on the other further back. It has standard armrests.

In the screen grab you post though, 17A is a better option (if you’re okay with sitting in an exit row) as it has more legroom and the seats in front don’t recline (I’ve selected 17D on a forthcoming SFO-MIA flight on a similarly configured A321).