I haven't had these pens for very long and haven't even used each color yet so keep this in mind when reading my review. Overall I like these pens. I purchased these to use specifically with the Rocketbook Everlast notebook (due to the recommendation of Rocketbook). I have NOT used these pens on regular paper so this review does not apply to such use. What I've noticed while using with the Rocketbook Everlast Notebook is that the consistency of ink flow varies from the beginning of the pen to the end. The flow seems consistent in-between, but theres usually a noticeable difference at the beginning and end for the most part. I've attached a shot of an example. The other thing I've noticed is that sometimes it takes up to 30-60 seconds to ensure the ink is completely dry. This would not be an issue except during times when I need to close my book and go....the wet ink will transfer to the opposing page. Rocketbook Everlast notebooks are not made of regular paper so they are not absorbent....therefore, causing a longer dry time. It would be nice to have ink that dries faster no matter what you are using the pens on (in which the ink would not dry out inside the pen either) - but this is just a suggestion to the manufacturer. Overall, for this purpose the pens are nice but I would like a faster drying time for what I'm using it for (hence the 4 stars rather than 5).
User Tip: To use the pen, push downwards on the top of the pen clip! It does not twist open. It also won't open by pushing on the tip of the pen. I tried those first. It took awhile for me to figure out how to open the pen for use.