So, I took the plunge and sold all my 5.1 kit in favour of Sonos - added Playbase, Sub and two Ones to my existing kit in other rooms and will sell off the Connect.
Because of my TV (one of the last Panasonic plasmas) I did have to buy an HDMI switch and finding one that's good, passes through 5.1 with an optical out AND compatible with Playbase was tricky so I plumped for the expensive option which cost £200
No regrets at all, the only thing really noticeable is the simulated surround feom 2.0 sources which obviously was much better on a £1500 AVR.
No wires, much more kid proof and lots of brownie points from SWMBO