I got my B3 a few days ago and since I have it, I'm trying to get it to work.
My first Problem was, that Sonos uses a Share like > \\b3\Music
But the B3 has only two top level shares, all others are like > \\b3\storage\music
This is not supported by Sonos. So You have to move down to the folder, through the folder structure. Not quite what I expected.
Why is there No User Interface Option to create a share, like on every € 100.- NAS? Like on a Linkstation...
Also the Samba Service is not starting every time on Boot. If You start it later on by turning it off and on again in the web interface or by command line, it works.
So I used ssh to create a folder, then made modifications to the smb.conf and at last some to the samba script.
Now I have a share \b3\musik and the Service is up and running.
BUT, I have payed around € 375.- for the B3 with a 500GB HD.

In my eyes a bit to much for what I have recived.
It is a really nice pice of Hardware, not that You get me wrong, but if I read Sonos support, I expect It to 100% and not that I'm having to open up several folders to reach my Goal.
But the biggest Pont is the problem with Samba and about that problem there are several Topics here.

So get Sambo to work out of the Box and a Option create Shares and You get a thumb up, for now, nice Hardware but the Software needs some improvement.
Just my 2cent.
Regards
Kyruss