17H-J are never available for advance selection - on longer flights, they are crew rest seats. On the last couple of SFO - JFK or return 762 transcons, they were released at the gate for those who arrived early and knew of them, or to one very happy couple that merely lucked out.

As to exit rows, I like the leg room more than any other thing, just about - 6'4". Otherwise, IMO, any aisle seat is almost as good as another, except the rearmost rows and 19. I tend to avoid bulkhead seats as they are often assigned to folks with ankle-biting critters and have no underseat storage.