The Wiim Pro is an unapologetic clone of the Sonos Port that manages to improve on that device's features at a fraction of the price.
Reviews for WiiM Pro and Pro Plus
WiiM Pro - Review & Measurements (Streamer)
Sonos News, Guides, Reviews and More 2
WiiM Pro Plus - Ten Interesting Points (Vs Node 2021 / Sonos Port / Argon Audio Solo)
Wiim Pro/Sonos question : r/BudgetAudiophile
The Wiim HiRes Streamer- Can It Compete with Sonos and Bluetooth for Your Vintage HiFi Stereo?
Bluetooth Speaker Reviews
WiiM Redefining Home Audio: Affordable, Innovative, Hi-Res Sound
WiiM Pro - Review & Measurements (Streamer)
Wiim Pro review: this could be Sonos' worst nightmare
WiiM Pro Streamer Audio Science Review (ASR) Forum
WiiM Pro Plus Takes on Sonos Port for Half the Price - CNET
WiiM Pro Plus Takes on Sonos Port for Half the Price - CNET
WiiM Pro Plus - Ten Interesting Points (Vs Node 2021 / Sonos Port / Argon Audio Solo)