Streaming: WiFi or wired??

+1 to @mike_in_nc and @almarg 's posts.

It depends. 

WiFi works just fine if your signal strength is good.  For a system the level of using the Kii Three I would look at the Aries G1 or G2 then you have the option.

I started off wireless and soon got tired of losing the handshake. Much more satisfying experience running Cat8 from an Ubiquiti switch. I think BluOs is the worst of the three player OSs that I have. In it's favor it auto indexes locall files and it plays any service without requiring plugin.
I just ordered a 4th streamer that looks like a game changer. Maybe August.

Bluesound wireless code is a trainwreck.  The Node 2i I'm trying out drops off the wifi network every few hours requiring a reboot to show back up.  No issues with any other wifi components on the network.  After conducting some research, this appears to be a long standing problem which Bluesound has failed to fix (among other wifi issues).  If you're getting a Node 2i (which is otherwise a nice fully featured streamer at the pricepoint) expect that you'll need to hook it up wired.

Using Node 2i on wifi. No problems.
Your mileage may vary depending on router and signal strength