It works very well for me. Very easy to set up and no drop outs because of a busy network.
Just make sure your PSU can power a DAC, WiFi dongle and a USB stick at the same time. If things stop working, that may be the problem. Check if you have enough free USB ports too!
I use a 64GB SD card, with most of my music on it, and the overspill on a 64GB USB stick. As Twerp says, it works pretty well. People say there might be issues with SD card ‘wear’, and possible corruption, but I’ve not experienced that so far. One possible caveat is having your music on the SD card might make upgrading to a new version of Volumio problematical, as you presumably wouldn’t want to flash over your music library.