I bought the Slim Click DLC and I am such a fan of your design now it’s not even funny. I have quite a few ‘boutique’ pens, but your two innovations almost make all the others obsolete.
First, the collet! Why didn’t someone think of this before? That distracting little click every time you begin a stroke, from having the 0.3mm mismatch between the Pilot G2 tip size and the other smaller tips is gone.
And then the super easy, tool-less, internal length adjustment takes care of the other complication when switching between refills. (Reading through some of the negative reviews, I’m saddened to realize that some other owners weren’t able to figure out how to use the adjustment. I hope they eventually did.)
As for improvements…I don’t like the other design, with the extra width around the grip section. Compared to the Slim designs, it seems an inelegant implementation of the length adjustment feature. If there’s any advantage to that design, you could make that clearer in the description.
Your current lineup doesn’t have a Slim Side Click! I’m sure this was just a terrible oversight. Please add it as soon as possible.