Ah yes, I'm actually thinking of the P&S discs that were done in '85. The letterbox versions were from the same telecine as the SC set. I stand corrected.

I have a set of the US pre-THX LDs and they don't really look very good to be honest. The color looks closer to the actual film, but seems to have an overall shift toward green, which I think has a lot to do with the age of the film at the time of the telecine. The THX cleanup they did for the Definitives took care of a lot of that. I'd say the color difference between these and the THX LDs is as close as any current DVD transfer compared to the official DVDs (i.e. a huge saturation difference). The big problem with these is the fact that the video is a lot softer overall. I would hope that the SC LDs don't have this issue.