I've had first hand experience of all the Sky HD boxes, and in all fairness the Samsung box really rules the roost. We had one installed last October and it has proved to be superb. It is not whisper silent, the hard drive and running fans make sure its presence is made known, quietly, but not totally inaudible!
The chief difference is the software. it is lightning fast compared to older Sky HD and standard Sky + units, this makes it a total joy to use and navigate on a daily basis. The picture quality is absolutely first rate, films on Disney Cinemagic HD are as close as you can get to Blu Ray, (in the sense that they are mildly lower quality than what you'd get from Disney's stock BD discs). Having watched The Incredibles this evening, switching from the SD channel to HD gives a perfect demonstration of the ability of the HD box - and an even better surprise? A Bugs Life in HD, absolutely knock out visual quality. The colours and smooth motion look superb on our Sony W4500. The DVD simpky comes knowhere close to this.
Sky have obviously spent a lot of time and money getting HD right, (so they should - i work it out that they must make an easy £40 million before overheads and churn costs every month!!), and it shows.
Thats my opinion anyway, others may beg to differ. The only blot on the landscape is the lack of ITV HD. This ongoing row between BSkyB and ITV has to be sorted, as when it does Sky HD will be a truly complete viewing experience.
It has been the 2nd biggest difference to our AV home viewing since our BD player. You can't give a bigger complement than that i think!
Roll on
Sky HD 3D.....
Westy