The UI is a confusing mess and a total faff to use compared to Spotify. Why on earth they thought that mashing up iTunes libraries with a streaming service would give a great experience is beyond me.
However, if I can get used to it in the next couple of months and the library is on a par with Spotify I will probably still swap for the above reason. £15 for a family of four is cheaper than Spotify who would charge me £25 for the privilege.
I just wish they'd realise the error of their ways and release an app free from the iTunes bollox.