I recently bought THE UNDISCOVERED COUNTRY on iTunes, which includes an HD copy of the Director's Cut. One difference in the transfer for the DC is that it used Nick Meyer's preferred taller aspect ratio 2:00 instead of the 2:35. Not surprising. The other difference is quite a freaking relief...
Theatrical Cut Blu-ray
Director's Cut iTunes
I haven't watched the Director's Cut all the way through yet. I've only been looking at bits and pieces such as above to see how different it looks from the blu-ray. It's not an amazing transfer, but compared to the waxwork/DNR'd-to-hell blu-ray the iTunes bonus looks like a godsend. I just hope Paramount one day gives this along with other Trek films a proper 4K remaster down the line.
Theatrical Cut Blu-ray

Director's Cut iTunes

I haven't watched the Director's Cut all the way through yet. I've only been looking at bits and pieces such as above to see how different it looks from the blu-ray. It's not an amazing transfer, but compared to the waxwork/DNR'd-to-hell blu-ray the iTunes bonus looks like a godsend. I just hope Paramount one day gives this along with other Trek films a proper 4K remaster down the line.