As for size, this is a jumbo-sized pencil, which is nice because it can be really hard to use normal sized eye pencils for highlighting areas (they are just too small sometimes!). Here is a size comparison between High Brow and a NYX Jumbo Eye Pencil. You can see they are roughly the same size.
As for the actual quality of the product, I was really pleased with how easily this goes on the skin. I've used a fair share of jumbo pencils that are dry/scratchy, but this went on really softly and was very easy to blend. I think the color is great for a highlight under my brows, but if blended I think it could also work on darker complexions without looking too light. However, this is very frosty. If you don't like a very frosty highlight, I would steer clear of this one.
This product retails for $20 and can be found wherever Benefit products are sold. If you like pencil eye highlighters and want to try something new, I think you will really like this product. As for how it compares to the NYX Jumbo Pencils, I do think the Benefit one is a little smoother going on the skin (and thus a little easier to blend), but if you don't want to fork out $20, the NYX pencils could give a similar look!
What do you use to highlight your brows?