SeatGuru isn't perfect but it'll be right more often than not with the seat dimensions, especially on popular routes.
Realistically I think airlines have figured out that they're mostly competing on price, not seat quality. Very few people price out flights and then choose the one that's $20 more expensive based on what the seats are like.
Realistically I think airlines have figured out that they're mostly competing on price, not seat quality. Very few people price out flights and then choose the one that's $20 more expensive based on what the seats are like.