I've bought the Guitarface II to be able to record my bass guitar in my DAW. At first, I tought it would be a simple and cheap solution.
Well... They said plug and play, and this is the truth. Plugged, detected, and ready.
Things gone worse when I installed the driver. Even without an instrument connected, sound was horrible, noisy, full of cracks, pops etc...
It took me a very long time to figure what was happening (Realtek chipset on computer, which caused an inside audio loop).
At the end, once the computer was properly configured, it worked like a charm. It allows to plug two instruments (yes, there are two inputs), but therre also are switches for using a simple input line, and better, use a microphone with 48V power (not tested).
The sound is clean and really neutral, so, it allows recording directly on a computer without having to setup a noise gate or declicker.
Same for the audio outs.. clean sound when in/out gains are correct for the source/destination.
So, for the price, it worth the value.
As a bonus, the interface comes with a software bundle. Some may find it useful, others no, but it exists, and I discovered IK Multimedia Amplitube with my bass guitar !