Found an original THX DVD of Spy. Compared it against the SE, UE and LD for some shots. The UE loses some of the color timing-especially the browns and is full of edge enhancement in the first half.

I think the THX and SE are the same. They have the same damage, same timecodes, same chapter stops and even the same chapter titles. Comparing against the LD you can see that the same source was used, but both on better equipment and slightly cleaned up as the dirt from the LD is gone and colors are better presented. I think overall I like the THX disc the best because there might be a little less edge enhancement than the SE. but I might be wrong. This hard to find disc is likely a port of the THX LD master as it arrived at the same time and features the 5.1 mix.

The problem I've seen with every SE disc is that the sources were way too grainy, and they are riddled with edge enhancement (and the first three are cropped to 1.78) but the colors are very accurate. The UEs take liberties that were not theirs to choose. And from what the UE Region 2 discs and UE Blus have shown there are differences between editions.

However with the new Blu-rays it might be possible to add back original audio via LD PCM and color correct to match the original editions. The only thing is the sheer amount of grain that was removed by Lowry's process.