Photoshop itself has really poor vector support and because your lines are so unique and appear hand drawn it's making me wonder how you converted the raster(pixel) brush lines into the vector format.
No offense but I am having a hard time believing that this is an actual vector. It would be nice to see the original file with my own eyes so I can put that disbelief aside. The number of people who are confused with that a vector actually is surprisingly high.
I could have sworn that [link] was a sketch and the artist didn't realize what a vector actually was. This piece is actually a pure vector and the artist had used thousands of single strokes to achieve this effect.
Sorry for not taking your word that it's a vector, it quite well could be. It's just so different from the normal style for vectors It would be nice to see it for myself
I guess a simpler way to put it is it's a combination of vector and bitmap. I just got into digital art, and I'm still working out some kinks in my usage of the pen tool, so I opt to use the Paths tab instead. It's vector lines over-top my filled, hand-drawn lines.
It's not "true" vector in the normal sense, in that I only used the pen tool and paths tab. I'm not sure what your definition of a vector image is, but I'm going to guess my image isn't TOTALLY within it.
Here's a [link] to the image when it was just vector lines, not outline, which is where I get those wonky, off-center lines. I'm warning you, it looks terrible without the outline filling in missing spaces.