Capt PS, think gear max extend speeds.
On the big Boeings it can be well below min speed in crz. Almost invariably there will be a level deceleration segment while the pax are all getting hypoxic. Boeing produced graphs - published in the FCTM - showing that, while the gear down option gets you to F140 in a little less time, only seconds, the gear up Vmo option gets you into the low 20s quicker. Hence probably less traumatic for the pax.
What if you are 3000 miles from the nearest bit of useful dirt and the reason for the emergency descent is airframe damage? Would you have the ba!!s to extend the gear and hope it will retract? Are you a good swimmer?