Maybe it's because I'm kind of set in my ways and use what I know it good, but I've honestly never noticed (nor used) these Sharpie Twin Tip markers before. I have used both separately and have loved them, but I have never actually seen these. However, now that I know they exist, I don't know if I can ever go back to just a single tip. The Twin Tip is so convenient and easy to keep on my person for all of the random projects that I may need a Sharpie for. As with all other Sharpie products, these markers do not disappoint. The lines are always bold and solid, no matter if I'm using the thicker or thinner tip. The permanent ink adheres to many different surfaces, making it very versatile. I've been using these for weeks and the perfect ink flow is still there. If you haven't picked up a pack (or two) of these Sharpie Black Twin Tip markers, I'd definitely recommend that you do!