Folks,
I have stalled a "Classic" (-200) in training, clean at high levels and approach/landing config. at mid-levels ------ the degree of buffeting and vibration is quite startling.
If you understand the different certification of the -400, close to a stall I guess it would be even more startling, because the horizontal stab is going to be even deeper in the turbulent wake from wing root.
The Classic simulator stall is nothing like the "real thing", the -400 sim. has the same shortcoming, based on my having done countless low speed sim.exercises.
The B707-320B/C stalls in the air are tame by comparison, the B707-300 even more tame, as long as you do not get into a dutch roll, again I am speaking from experience.
Final comment, we have a lot to learn about downwash from an aircraft above, I have had some mild encounters holding in the vicinity of EGLL and EGCC, and consider the recent written off Challenger near Dubai.
Tootle pip!!