To my eyes, digital cable was no better or worse than regular cable. As was always the case, the premium channels looked great. The other channels were all over the place in terms of picture quality.
Since you are asking specifically about Sony XBR 450 the other part of the equation is Digital Reality Creation. The newest generation of XBR due out any time now, will have adjustable DRC. I believe this would be a worthwhile feature for any cable viewer.
The only other thing I can think of is that Consumer Reports recently tested big screens and they found that the Hitachi 53UXD10B had very good picture quality with standard definition material (cable, satellite). This set lists for $2,500 and can easily be had for $2,250 or less at Sears. Totally different beast, but if you have room for a 53, I'd go for it.
Thanks for the info Arthur. I really need a direct view, 4:3 tv as I will be doing a good amount of gaming on this set and dont want to risk the burn in on a big screen. Any idea when the new xbr set will make an apearance? Do you think the geometry will be improved with the new flat screens including the new xbr? Maybe hard to predict, but what do you think?
If digital cable is anything like digital satellite (and I think they're probably pretty close), then my experience is that it'll look pretty darn good once the set is reasonably calibrated. My folks have this set and DirecTV and I'm very impressed with the results (so much so that I'm seriously looking into getting one of these sets myself).