Flew this route last week. No 787 but included brand new 737-800.
Connection in MEX is tough/long as must waste 1.5 via customs. Recheck via security via MEX is easy/quick! Don't print out web onlinein BP as not valid in mex and will need to visit kiosks.
Aeromexico lounge is comfortable with waiter service and various well drinks available.
Food is just average/fair. I found service was good but slept part of flight.