I had to revive this old thread as it almost exactly describes the problems I am experiencing with my new Samsung UE40H6400.
The Motion Plus feature is totally unusable on anything other than Clear.
On the Standard, Smooth and Custom setting the picture will stutter or drop frames on certain panning or moving scenes. Not all the time but enough to be really annoying.
This happens on any input and from the inbuilt tuner.
Every day I record a tv show called Hollyoaks in HD on a Humax pvr.
At the end of the show the credits scroll vertically with some video content to the right of the credits.
With AMP Off or on Clear the movement is fairly natural and smooth.
With AMP on Standard, Smooth or Custom the scrolling credits turn into a hideous jumping mess that literally jumps several inches on the screen. It jumps then stops then jumps again. It has to be seen to be believed. It looks like the AMP is activating very violently turning on and off!
It is so bad that it looks like the Tv has a serious problem. This even happens with the Custom setting set to Blur 0 Judder 0.
I connected my pvr to a friends 2013 48 inch Samsung 8000 series tv (not sure exactly what model) and guess what. It behaves in exactly the same way!
I have experimented with almost every possible combination of settings and have settled on Clear as this generally removes 25fps judder and only introduces very mild SOA. I can live with the tv as the clarity and colours are good for the price point and DSE and uniformity are acceptable.
It is hard to believe that this issue has still not been addressed and I guess it never will be.
Most people seem to except that their brand new expensive tvs are not perfect or think that it is acceptable.