The Avionics update that they did for the 747 and 787 was a huge improvement. But on Xbox at least it completely broke those aircraft. Many times fixes have been promised but they’ve never actually yielded results. Thought I’d give the 747 another go yesterday and it was stuttering so badly that after 4 hours of real time, only 2.5 hours had passed on the sim. I don’t get these issues in any other aircraft; not even the inibuilds A20N v2 that everyone moans about
BravoAirspace did a mod for the 787 that fixes the issue for that but nothing exists for the 747. It does beg the question though - if BravoAirspace managed to fix the 787, why haven’t Working Title managed to fix the 747?