I normally have a rock-steady WiFi network and never experience any dropouts.
I use Spotify music a lot - streaming from both MBP & iDevices to numerous different airplay speakers. A mix of both Airplay enabled devices and some connected via Airport Express or ATV. Never experienced any unwanted noise, dropouts or stuttering on any of devices.
Recently, I added a Naim Muso QB 2 which I’m using via WiFi - since adding the QB, I notice lots of dropouts or stuttering but only on the QB. None of the other devices connected at the same time suffer. The QB will begin to stutter then invariably the music stops completely whilst the QB still shows as connected. Sometimes it shows as disconnected.
I’m also running the Qb 2 but haven’t had this problem personally. My initial thought is that this sounds like an interference problem that you’re having. Are you runing multiple devices in the same vicinity as the Qb?
If there’s a lot of congestion at the 2.4Ghz frequency band (bluetooth devices + other network devices connected) it can cause problems. I would advise try turning off other devices and see if the problem persists.
Using Qb2 outside on a roof-top patio just 10 feet away from an indoor wifi repeater I experienced multiple drop-outs and had to revert to running a LAN cable to the repeater.