I was just reading about the dart. Why would this work better than just filling the cart with foam like I do now? I have heard that if you compress the foam too much, it won't wick. This has proven true in my experience. So, compressing it in the straw, I wouldn't think it would wick.
I'm just trying to figure out the physics of the thing.
~A
the difference between the dart and the slug is that with the dart you are sacrificing a drop or two of liquid per refill but it is much easier to make, leaks less (at least for me), and i have never had a dart get stuck on/under the bridge as i have had with the slug.
EDIT: oops, i should probably read what you actually post instead of what i thought you posted.
the difference between using a foam dart and using the foam as filler is that with the dart there is an open chamber between the base of the reservoir and the foam touching the bridge of the atty. why is this important? air is less dense than foam therefor you can fit more liquid in a cart and liquid can flow through the chamber faster than it will wick through the foam so faster wicking speed overall.