Focusrite ISA One Analog

It offers very limited tone control for guitars. There's just 1 gain knob that can be used to control guitar gain (or volume). I was surprised to discover that even with minimum (10db, if I'm not mistaken) gain setting the output signal's peaks reach clipping levels. Not always, but happens. I felt to turn down it a bit, but there're no means to do it. All other volume or gain controls work only with mic / line.
Other thing I was confused about A/D converter on interface. So, it's absent. If you need it, it can be bought separately and on the back there's a place to put it.
Overall, guitars sound just a tiny bit brighter than with default motu m4 hiZ inputs. I didn't find it sufficient for buying it.
VU and peak meters on front pannel are just for visual pleasing. There're 2 regulators on the back that adjust their sensitivity, so basically, you need to calibrate them on your own. And yes, VU meter is useless naturally. Though may be fun to see pointer moving.
Bu the way, It's quite bulky. I was surprized by its size.