Howdy B-)
I will make this quick. Basically I'm currently using a Scarlett Solo (3rd gen), along with a pair or KRK studio monitors (speakers) and Sennheiser HD 6XX headphones.
My issue is that the volume knob controls both outputs. So if I want to ONLY use my headphones, I need to turn off the studio monitors. And when I'm not using the headphones I just unplug them and put them aside and turn the monitors back on.
It's not a big hassle, but it isn't necessary. For example, my friend recommended the Steinberg UR22C, as it has 2 independent volume knobs. However I looked at some reviews and ultimately that product has too much background noise/hiss for recording with my condenser mic (Audio-Technica AT2020 -- I should note this REQUIRES 48V phantom power).
Another solution would be to get a passive audio switch, but the problem with those is that the cheap ones don't output equal volumes to each monitor, which CAN be fixed, but I read from multiple sources that a cheap passive switch like this actually DEGRADES over time. And the expensive ones are, well, expensive. At that point I'd rather get a higher end DAC and call it a day.
Just curious if anyone else has had this issue, what you did to solve it?