They didn't train us on this stuff, so these are just my own observations/assumptions:
MTS Classic TV is digital, but I believe the content going from the receiver to the TV is analog, which is only 480i and is full-screen all the time. With Ultimate TV, the receiver is (or should have been) set to output 720p or 1080i.
So if the SD channels are still only 480i, my guess is SD content on Ultimate TV is being downscaled from 720 (or 1080) back to 480
Or that watching 480 content at an HD resolution makes it even more apparent how crappy non-HD content is. I dunno, I think I'm starting to confuse myself, haha.
Since I started doing this about 3 years ago, I've had countless customers complain about the picture quality on their flat-screen TVs. Some of them had Shaw analog cable before I got there, yet for others it was the first time they got to see their new TV in action.
I'm assuming that Shaw analog cable tends to have a smoother appearance over their digital TV or MTS' digital TV, where there is obvious "blocks" in the picture. And I don't mean when the signal breaks down and shows pixellation.
I don't know how accurate that is, but that's my take on it.