|My camera really sucks|
I love the Pental Pocket Brush. It is a brush pen, but not like the normal felt-style brush pens such as PITT or Tombow. Instead, the Pentel's tip is "real". That is, it is composed of actual hair-like fibers that come to a point and behave like a real brush. If you've used a synthetic brush (not made of actual animal fibers), then you know what this brush tip is like. It's basically the same.
The Pentel uses little cartridges, so when it runs dry you can just snap a new one in there. The tip is also replaceable, although honestly these tips don't seem to wear out. I'm pretty gentle with my tools, but if you're aggressive perhaps you'll have to replace it eventually.
Being a real brush tip, it is much softer and flexible than regular brush pens. The PITT, for example, has a firmer feel. You have to press a little bit hard to get it to produce a wider stroke. The Pentel will flair from micro-thin to very wide with the slightest pressure. This gives it a nice flowing vibe, like it is dancing along the surface of the paper.
The pigmented ink is typical for brush pens. I don't have any issues with it. The ink goes on dark but may fade a little with erasing, same as PITT, Tombow, Micron, etc. It takes alcohol markers like a champ.
There are some cons, though. Depending on your needs. For example, I actually love the tighter control of a PITT or Tomobow brush pen. Especially a nice, crisp, new PITT. You can't beat 'em. But the PITT's tip is fragile and will very quickly lose it's point and become a stubby blunt tip good only for fat lines and fills.
The Pentel retains its fine point. You can get ultra-thin lines with a careful hand. And, with a quick stroke, you get a nice dry brush effect.
Another great thing about these tools is they are relatively cheap. Last I checked, it was about $15 for the pen and 2 ink cartridges. You can get 12 ink cartridges for about $10. I checked on tips, but can't seem to find them anymore. Maybe they stopped selling them separately. Which is fine... just buy a new pen if necessary.