I'm not sure what selection of LEDs if any Drew has - but I got the silver (basically no paint job) batteries with orange LED. I'm not picky and I like the stainless steel look on stoofs...
The KR carts are not a simple replacement on filler material at all. I've tried many times... all of them were hours spent on each, none of them were ultimately entirely successful. The main problem being that the atty 'element' wire is encased in the filler, and also encasing the filler, so pulling / cutting it out is almost impossible to do without damage to the atty. If you are able to do it, then you have the problem of filler material right on top of the atty coil and if you have burned through the special wrapping material, then unless you go buy special siad materials, you will instantly melt Fluval, Nylon, or Filter type materials that I have tried.
Refilling them several times - rinsing them out when they seem to get harder to draw / aren't accepting as many drops during refills, etc. are the best way to use these. AND they are great cartomizers. I am not knocking them one bit at all. Fantastic stuff.
I just like the Greencig ones because I can drip them if I want to so I can try out flavors just like I do with a regular atty, and I can replace the filler if I ever need to, and the build quality just seems a bit nicer. As my wife says though... I'm kind of a tinkering picky .......!
- Hap