The reason I'm hesitant to pay the $90 is because sometimes those seats tend to be in wonky configurations. For example seat guru sometimes says they are good seats, but once I picked a seat based on the seat guru recommendation, and it had a misaligned window. Not to mention, sometimes the trays are in the armrests for those seats, which makes them kinda ishtty.

In this case the only window seat that shows available both on latitude and my own seat map, is 12 K. Seatguru says this is a good seat, but I'm skeptical based on that bad experience.

FWIW it was an aeroplan ticket and the plane is the 39 row 767.