This looks great! I’m super happy with my MK4, and have never had to do anything with it after the initial kit build and re-seating the LCD cable to fix some early screen-blanking issues.

I’ll probably skip this for my own printer since it seems like most (but not all) of the speed up comes from layer height, but $99 is not terrible for anyone who gets value from it. And anyone buying a new printer gets this stuff with no price increase, which is nice and makes the MK4/MK4S even easier to recommend.

I didn’t know how much more dimensionally accurate Prusa’s prints are compared to the competition, but it makes sense now why there are so many calibration models online if that just isn’t the way every printer works. I’ve designed some parts that need an 0.1mm first layer because I’ve never had any failures with that, but I guess if I share the STLs other people might have trouble.