Here are a couple of pics of my '17 Micra SR before and after lowering.
I forgot to take 'before' measurements so I don't know the exact drop in mm. It looks like it's about 30mm-ish as Tanabe states it should be.
The car has a very comfortable ride considering the upgraded handling. It's stiffer but not bouncy or jarring.
The car also feels much more predictable accelerating, braking and cornering. A huge improvement overall and it looks good too.
The shop that did the spring install also did a full alignment and camber adjustment, so I'm now running -0.5 degrees of camber front and -1.5 degrees rear.
The springs are Tanabe Sustec for Micra/March K13, p/n: K13DK. I believe the springs are available overseas only and need to be ordered from Japan.