It has the advantages of simple structure, convenient carrying and smooth writing. The disadvantage is that sometimes the water is cut off and can't be wiped off casually.
The water-based one is easy to hold, just to keep it good. It is best not to write with a water-based pen, because when it comes to water, the neutral one is oily. Easy to save, not easy to blur handwriting.
Water-based writing is smoother, and the words written have a sense of frustration and rank dispersion, which is more beautiful. It can be used to practice calligraphy or participate in competitions, and there are also special ones. Neutral ones are easier to decide and the strokes are not obvious.
There is always its own length, water-based is not easy to write on cloud paper, and neutral is ok.