I was prepared to downgrade this speaker because I wasn't getting great audio with Bluetooth connections. Even using my high-end desktop and multiband equalizer, the sound quality was very thin. It turns out that it was mostly the fault of Bluetooth limitations.
I tried this again with other high-quality sources and found the audio quality to be quite impressive for a speaker of this size. Using lossless files on an SD card presented much more solid frequency response and surprisingly room-filling volume in my media room. Similarly, the RCA coax connections to a high-end surround sound system provided a solid center channel experience.
The cabinet has a unique appearance with the grey fabric, wood grain and exposed wood surfaces. The cabinet is heavy and solid and doesn't cause any resonance.
Here's why it's 4 stars instead of 5 stars. The instructions do not match the actual functions provided by the unit. You are supposed to be able to toggle various inputs including a USB flash stick but the USB-A connection is actually a power output so you can use the speaker to charge other devices. It would never toggle to the "flashing green" USB drive mode. The other inputs all worked as described - Bluetooth, MicroSD, Line (aux) and RCA coax inputs.
This is battery powered but it isn't a portable speaker because of its weight and the exposed elements. I'm not sure if I'll leave it permanently at my desk for my computer or attach it to one of the bedroom TVs that can use better audio.