I’m pretty sure I read that Miracast creates it’s own wifi network rather than using the existing house network (obviously it must use the house wifi to stream the content on the phone in the first place).

You’re right that Miracast creates it’s own peer to peer network (WIFI-Direct) between the streaming device and the receiver but you’re still limited by the capabilities of connection technology on your devices, which will be a, g, or n – depending.

well folks thanks for the advice, I called in at currys today and swapped it for a sonos play 3, play 1 and a bridge.

Now i can flog the wireless sony setup i had and the mrs might actually use this.

cheers