Bluesound node 2i

The Bluesound Node 2i is a nice piece and good value for the money.
Like most of its competitors, more often than not, it will behave and perform better using a wired connection.  There are few streamers that actually are designed to perform better using a wireless connection, with some of the Auralic offerings (with much higer price point than the Node 2i) among the notable exceptions.  You will tend to have less dropouts and better resolution going the wired route, especially with hi res material streamed over the internet.

I use my Node wirelessly (on the 5 ghz band). 
I have never had any problem with dropouts, -which would be the main issue of using wireless. If you have a good signal, you should be fine.

Is there a difference between ethernet and wireless?
Maybe, but I haven't noticed it, but, then again, I am not anally retentive about such things. If it sounds good, it is good.

The only other streamer I would consider is the Aurender N100.
A bit more than the Node, but very, very good.
The main drawback is that it only works with Qobuz and Tidal, whereas the Node has a greater number of applications to choose from.
Bob

I think it depends on how clean your wireless is. If you are in an apartment building or condo and have lots of neighbors that are clogging up the wireless channels, you're like to have more dropped packets which can cause issues. Generally, the 5Ghz band is less crowded and is more likely to give you better performance. 

I live in a city, but in a neighborhood where the houses are a fair distance apart. I have four Node 2is as part of my network (along with a higher quality Bryston streamer on my main 2-channel system) and have used them both wired and wireless with good results.