I watch hardly any telly but I've still got Now TV because it gives me access to some channels which I like to watch occasionally.
Here's a quick summary of what you get:
A Now TV box that's not got a current 'Pass' turns a 'non-smart' TV into a 'smart' one, enabling you to watch catch-up services (such as BBC iPlayer, etc) on your telly. There are other free apps too, such as the one which enables you to watch Youtube content on your TV screen.
Most people though subscribe to one or more 'Passes'. (There's no contract. You can stop and start your subscriptions at any time).
I've got the 'Entertainment Pass', which gets me Sky 1, Sky Arts, Sky Living, Sky Atlantic, Gold, Fox, Comedy Central, ITV Encore, MTV, Discovery Channel and Nat Geo Wild live, plus access to some 'box sets' on demand. It costs £6.99 per month.
There's also a Sky Cinema Pass, giving access to over 1000 movies on demand, as well as a Kids Pass (6 children's channels for £2.99 per month) and a range of Sky Sports Passes. (They give unlimited access to all Sky Sports channels, except pay-per-view events such as World Title boxing matches. A single day costs £6.99, a week costs £10.99 or a month costs £33.99).
An 'ordinary' Now TV box (£14.99) doesn't have any kind of recording facility but a Now TV Smart box (£39.99) allows you to pause and rewind live TV (although it still doesn't allow you to record and save programmes).
http://www.nowtv.com