I've been playing with my pens for a while, and I like them all for writing.
They're smooth writers--no drag. They are quick-drying, but with the exception of the marker pen, you can smear them within the first few seconds. For their price range, these are decent pens and I won't hesitate to purchase more of them in the future.
My favorite is the marker pen. It gives a nice bold line, and glides across the page.
The Ballpoint forms blobs on the tip that take longer to dry and thus increases the chance of smearing. It isn't as noticeable when writing, but very noticeable when drawing. I also found that it jitters a bit if you write too quickly and leaves a more jagged line.
While, the Ballpoint is the weakest performer, I was pleased with all of them. I do prefer them for writing, and they'll be my daily purse carrys that I use for both writing and doodling while standing in line or waiting in offices.
TŪL RB2 Rollerball Medium 0.7mm
TŪL BP3 Ballpoint Retractable Medium 1.0mm
Marker Pen Fine 0.8mm
Other Reviews of TŪL Pens:
Letters and Journals
The Pen Addict
The Well-Appointed Desk