As you say, it saves about 10% (taking audio into account) but with over 100 channels, that's 10 additional channels - a lot of bandwidth and probably a lot of transponder money. BTV also compresses the signal on all channels in addition to changing it to 720P, so there are additional savings there. Depending on the Cable provider, some channels are compressed, others are not. Compression of course is not the only criteria for picture quality, so let's not go there in this thread.How much bandwidth does it actually save?
In Australia there are no TV channels broadcast in 1080p , there 1080i .Which is unfortunate. I know in Australia they're full 1080p.