In my opinion the 2 obvious improvements are :-
1. while watching tv you can now select the 'i' button and get information on any program by scrolling through 'now and next' bar for all channels, whereas you could only previously do 'i' on the channel you were watching.
2. whilst in 'tv guide' you can continue watching the channel you were on, or watch any channel currently showing, instead of the rubbish Sky Tv Guide music that used to happen, so you never miss a thing.
As said in another reply, if you don't like the smaller selection of channels listed in the 'tv guide' - 6 as opposed to previous 10, then select the option not to show the preview screen and you then get 11 channels listed along with the audio from the channel you were watching, so again this is an improvement.
I like it.