If you want the utmost in the quality of the music, you must first start with high quality files. I don't know what the capabilities of the iPhone are. Will it play files with a 16 bit sample size and 44.1khz sampling rate?
If so, I suggest that you rip a few CDs (even if it's with iTunes), put those on your phone and play them. That will give you somewhat of an idea of what a Sonos will sound like.
In any case, what you are streaming from MOG is trash in comparison to what you get by ripping a CD in some sort of lossless format. If MOG is all you're going to listen to, don't bother with throwing any more money at equipment.
The benefit of the Sonos is that you can rip all of your CDs into a lossless format and get CD quality sound without having to mess with CDs.
If so, I suggest that you rip a few CDs (even if it's with iTunes), put those on your phone and play them. That will give you somewhat of an idea of what a Sonos will sound like.
In any case, what you are streaming from MOG is trash in comparison to what you get by ripping a CD in some sort of lossless format. If MOG is all you're going to listen to, don't bother with throwing any more money at equipment.
The benefit of the Sonos is that you can rip all of your CDs into a lossless format and get CD quality sound without having to mess with CDs.