The iFi Zen Stream is a great streamer, you will enjoy it. It does Wi-Fi very well, but I have mine hard wired and connected to an extender. But before that, the Wi-Fi worked great.
Now, to get the best sound quality, get yourself an external hard drive and load all your music on it, connect to the Stream via the USB port, and use the iFi app to play your music. This eliminates the need to use AirPlay, which is the biggest degradation in SQ. If you have Tidal, it also has Tidal Connect for best sound quality directly through the Tidal app.
If you use AirPlay, you are going to defeat the purpose of a dedicated streamer IMO.