My input is the computer (foobar2000 with wasapi, kodi and other movie players), and a portable CD player. It is easy to toggle the direct mode/off but I do wish there is a tray shortcut.
The best thing is that line-in works when USB input is enabled. When I want to listen from the CD player, I don't have to unplug the USB input.
(forget to mention the device selection in either Windows 10 or in foobar2000/kodi also makes it very flexible.)
Initially my biggest concern was the delay as a USB device. I had a $5 USB sound card before, which was quite unresponsive or had jitters. But I found this one plays instantly.
One issue in Windows 10 though is the device stops working after computer resumes. The light flashes and I have to unplug it, plug it, repeat maybe several times. Once it starts to pick up the signal then it would continue to work without problem. I don't think it is a hardware issue, just the driver fails to initialize it properly.
It does not work well with a Mi-box (an Android TV device). There is loud crack sound once in a while. It works in Fedora Linux without such issue.
It is quite small, not bigger much than a pack of cigarettes. I got it for $75 at Best Buy clearance. I'd like to buy another one to avoid carrying it though, to reduce the work of setup, and to avoid repeatedly plugging in the wires. Somehow I feel audio devices are more delicate.