Looking at a biz class trip from GRU to MEX to LAX. First leg would be on a 777, second on a 737. From seatguru maps, it appears that biz class is the top class on the 777 (a rarity from what I've seen). 737 would be single-aisle 2x2 seating. How is the service overall? Biz class passengers have access to an Aeromexico lounge at GRU and MEX? We've never flown Aeromexico.