Thanks for the reply and I can only hope I have done the right thing as I have just ordered an M11 to take away on holiday in a weeks time.
I have been agonising about getting the M11 but I could not live without the BBC Sounds app and use Tidal for all my new music. So I have been talking to someone in the BBC and he says it should work but they could not support it and he pointed out that I could always use the BBC website and access everything from there. When it comes to Tidal I did a quick search on this thread and read a post from someone who had installed it but just to be sure I disabled Google Play and Services on my X5iii and sideloaded an apk and it worked.
Maybe some apps with financial functionality will work without Play Services providing you administer them on another device and don't try to buy anything on the M11. I really hope I will be OK and don't have to send it back. I just can't afford or justify buying the DX220 which is not far off double the price - plus I have grown to have a soft spot for FiiO.
Would anyone who is successfully running Tidal just put me out of my misery and briefly confirm that it does work please ?
M11 comes preinstalled with "Applications" app that lets you download (I assume) tested apps. Tidal is in here, very easy, and it works fine for me.