KingoftheRoad - you are right - AIRBUS has a service bulletin to remove it from all existing aircrafts prior to its baseline deletion - however, they crowed like hell about it ( white papers ) when it was rolled out - I think Boeing only uses it for ride comfort to relieve sharp motions.. However, the A321 has "lift dumpers" - I would imagine, since the A321 is pushed to its absolute limits from a wing design standpoint - It probably has "it" - I do think it was very clever of AIRBUS to extend the aft loading of the A321 wing by re-profiling/extending the aft supercritical cusp using new - super extended & profiled split fowler flaps - These Airbus folks are almost wily in certain areas ..