This long weekend is off to a great start. My pair of Karas Kustoms INK pens arrived, fresh from their Kickstarter campaign. A few initial obervations:

the tips are interchangable ! I did not know that. So with two bodies, I can use either one with the fountain pen tip or the ballpoint/rollerball tip. This is a very nice surprise.
the click is highly polished -- looks nice but will probably get scratched over time. Compare with my Retrakt that clip is less polished.
A small disappointment -- neither the Pilot Acroball nor the Pilot Juice, nor the Muji gel refill will fit inside the INK. The tips in both of those refills are thicker than the Schmidt refills. I have not tried a Hi-Tec-C refill yet.
This is the first time I tried the Schimdt P8126 refill (came with the INK). It is very smooth. The line is slightly thicker than I want but I think I will like using it.

I think the INK is Karas Kustoms best pen yet. I have a prototype/raw Render K, an Aluminium Retrakt. I like them both, but I think I am going to like the INK most.