Exit row window seats confront some of the emergency slide and door, which curves inward somewhat. 30A/L doesn’t have that issue.

the seats are the same width but feel narrower because of the Solid armrests, so your hips/butt can’t spread into that space. That may or may not matter depending on your girth.

im personally a fan of 30A/L if you want a window because you can usually get out without having the middle/aisle pax get up.