The Placette remote volume control works very well. It offers something like 128 discrete steps and the manufacturer can set the level of the initial "on" step to match your needs. It does not have provisions for setting balance, but it does track extemely well between the two channels.
I have a linestage with a built-in welborne remote control of volume, balance, input selection and mute. It offers 60 steps of attenuation. While the differences between steps are just about right (i.e., not too large), the total range covered is not enough for me. The lowest level is not low enough and the highest level is WAY short of what I need to drive my Stax headphone amp. The Welborne is also sensitive to high DC offset at an input and locks up and refuses to operate whenever I select a phono stage that has a bit of DC offset. That said, the builder of my linestage selected it because he thought it was one of the best sounding attenuator of any type that he has auditioned in his design.