VistaVision is a perfect match to Blu-ray, and this is no exception.
TCAT looks very good. It is not quite as good as White Christmas, but that one got the royal treatment I suspect.
A number of scenes were originally grainy and remain so, but when it is good, it is great. Cary Grant's famous "purple shirt" that always creates a moire is still there, but looks almost perfect this time. Cinematography Oscar.
The sound is also quite good. VV was never into sound, but this has obviously been made from the original magnetic recordings.