Have you - in your reviews of the XE900 series - noticed any major motion artefacts (with Motionflow disabled) on 50/59.94Hz native content? (i.e. not 23.976/24 or 25p acquired stuff - but 50/59.94Hz stuff like entertainment, sports etc.) My 49XE9005 and another model I've tested are both suffering badly from frame drops and out-of-order frame pair repeats (in 720p50 or 720p59.94 domain). I've tested two TVs - and compared them with a 49X8505B previous generation model with the same test material fed via an HDMI splitter.
The test material has burned in 720p50 timecode - and I have filmed it in 720p240 slow motion for analysis using an iPhone. It is clear to see that frames are being dropped (usually on shot changes) or shown for just 1/100th of a second instead of 1/50th in some cases. These are not hugely visible to the naked eye. However these drops are having to take place because of the repetition of pairs of frames - which most definitely ARE very visible.
Example :
Frame sequence 1, 2, 3, 2, 3, 4, 5...... N, N+3
The judder of seeing frames 2 and 3 repeated after they've already been seen is really clear (it is often after shot changes - but you can still see it a a judder). The dropping of Frames N+1 and N+2 is less obvious as it is usually on a shot change as well.
It's consistent across multiple TVs with the same settings - and happens usually at the same timecode.