Mr. Buster is 6'3", and we have flown SQ coach long-haul several times. SQ is pretty good about giving tall people the exit row seats, so I would definitely try to get an exit row seat. One warning, however, is to avoid the window seat in the exit row. The door bulges out into the row such that the leg room is actually worse than in a regular seat. Exit row aisle seats are extremely roomy. Maybe Mr. Buster will be able to chime in here and give you more info.