Have it in about 2 to 3 weeks now - and have noticed that programmes that I could see on my ordinary Sky - eg, Sky Documentaries, Sky Atlantic, Sky Comedy etc - if it goes into Catchup and if I want to look at them - it says at the top to upgrade my package.
Now, do you have to pay for Catchup. which I don't want to do as I'm paying enough.
You do choose your catch up. If you miss Coronation Street tonight you watch it tomorrow 'on catch up'. You catch up on programmes that have recently been shown and the channel provider allows access to it.
On demand is programmes, films and box sets that Sky provide for you to watch but they have not been recently broadcast on its channels. It is an additional service that gives extra choice.