Personally sonos is my favorite music distribution system. It's easy to add to, easy to use and so much music content out there. That said, in no particular order:
- Sonos does internet radio better then control4, most because sonos manages the links where as control4 your dealer does or you can.
- Sonos does music files on your system better then control4, again because sonos will scan easier. Control4 again needs your dealer to scan and manage or you can with control4 software.
- Both have rhapsody, I have not used it on sonos but with the exception of a recent account saving glitch it works great with control4.
- Sonos does Pandora, control4 does not.
- Extra Vegetables makes an app to control sonos, I have heard good things but not experienced it myself.
- Amplification. Control4's amps are better then sonos, but unless you have to decided to use very inefficient power hungry speakers for background music this is really a moot point. Example: i had a customer who decided to use Martin Logan electrostats off sonos, then moved them to a control4 amp then to a rotel receiver, the sonos was the worse sounding with them. But all the other speakers in his house really didn't sound much different moving from sonos to control4 power.
- NAS drives - i would highly recommend using one for whatever system you choose. Having to rely on a desktop or even worse a laptop to be in good running condition to stream mp3's and itunes is a recipe for annoyance. And yes, someone in the house will ALWAYS shut it down at some point that you will be unaware off.
- Control4 keypads. You said you were not interested in them but I would recommend at least the 3 button to keep in rooms for volume controls. With the ipods / ipads you have to get them out of sleep mode, they re-establish your wireless network then reconnect with control4 then you have to switch rooms if you are not in the right one. Sure all this only takes a couple seconds to about 10, but I find it very annoying when you need a simple volume up or mute command.
Remember control4 is a complete house solution, basically limited to your imagination and wallet. If you want you can use motion sensors to turn lights on and off in rooms, you could also carry that into music playing. If you have speakers in 2 rooms next to each other but only playing in 1 you could have that second room also playing with the first when you walk in and have the previous room shut off if after x minutes the motion does not sense you. I'm sure you are aware of other things control4 can do.
Sonos is just a music distribution. The nice thing is you want to add music down the road you can do it yourself (outside of connecting to control4 amps) such as Play5's or Play3's in any bedrooms that are not part of the house system, or a garage or a basement, etc. You don't have to worry about bringing in your installer for running wires and programming new rooms.
What I would recommend is a combination of both. Decide how many streams of sonos you really need at any given time and just add those zp90's to the control4 amps. Sonos just provides so much music easily that it should be at least 1 source in house music systems.
who ever said money can't buy love never bought a puppy.