Firstly, I am a custom installer and had been successfully using/installing SONOS for many years on a commercial basis. These are a few problems which Im going to assume many of you are experiencing. (and bear in mind SONOS before you blame the networks-they are fine!)

screen delays

no NAS allowance (I require this for installation in remote areas where no internet)
no landscape interface on ipad/iphone-We wall mount iPads with SONOS, Control4/Crestron interface requiring landscape mounting.
when manually grouping arc and amp-loses grouped volume. (where no hard wire is possible to link)
no downgrade to S1
volume slow to engage
interface slow to connect-(imagery takes long time to appear)

difficulty in connecting new products-many errors encountered

why is pin at bottom of amp-cant get to it when in a comms rack

generally the app makes little or no sense opposed to s1/s2-bring S2 back until you sort this mess out.

can get rid of popups even when opting out.

ads and unnecessary options appear on home screen.

something has defo changed since new app launched-remember this affects hardware too as both hardware and software have to align.

should go back to S2-very little problems (funny that!!!) 

i have multiple systems all over Scotland-so many complaints.

...And to finish tech support appears to be no longer available -cant get through on phone nor are forums/emails answered by sonos-the community are having to so many probs or just live with it.

its a disgrace sonos, clearly we are all fed up! Im losing customers