Thanks for the excellent report on the Samsung NX1. When you go back to see it again, could you please check out the quality of 1080 50/60P. Since the full res sensor scan tops out at 30P, I would assume that 50/60P would have either line skipping or binning. But, the question is, what does the picture actually look like? The Sony A7s has a similar problem when doing 50/60P in full frame mode. In that case, the picture is quite low res.
If it turns out that the NX1's 50/60P picture is similar to the A7s, could you suggest to Samsung that they provide a crop mode on the sensor in order to get a non-line skipped readout at 50/60P.
Hope that all makes sense, and thanks again!