I needed audio interface for my (stereo!) keyboard and condenser microphone and so I decided for Yamaha AG03 Mk2 (Focusrite 4i4 was another option). There are many AG03/06 Mk2 reviews on Youtube, so I will only summarize my impression.
AG03 is very solid made and doesn't feel cheap at all. The only thing that ruined this impression, is linear fade potentiometer for microphone. It has no damping and so it doesn't give "smooth" feeling when adjusting.
Why I decided for AG03 and not for 4i4? Because AG03 can also be used as standalone mixer (without being connected to PC), as all important settings are physically onboard.
The only downside I see (compared to 4i4) is, USB audio output only has two channels. That is, there's no stereo (L+R) channel for keyboard and separate channel for microphone.