The Uni-ball Fusion has a 0.6mm line width (not 0.8mm, as I mistakenly wrote in my writing samples), and is available in blue, pink, purple, and grey. I picked up a 2-pack with the pink and grey versions. The Uni-ball Fusion has an eye-catching appearance, with its white colour and floral design on the barrel. Some people may find it too "girly" but I think the floral pattern is fairly unobtrusive. Overall I find it an attractive pen.
The Uni-ball Fusion writes smoothly, but I did notice that the colour of the ink when laid down on the page is not uniform. I don't know if you can see this in the pictures or not, but some parts of the letters are darker than the others. This was most noticeable in the grey and reminded me of how ballpoint pens sometimes form globs of ink at the tip. I don't know if a similar thing was happening here. The grey ink had a bluish or purplish tone to it (I would have preferred a more neutral grey) but the pink ink was a nice bright shade (although I have to admit I'm not a pink person).
The most unusual thing about this pen is the ink itself. The "ink" in the barrel is a clear, somewhat milky fluid. Obviously, somewhere between the barrel and the tip of the pen the colour must be added. The package reads "ink starts out clear and flows to color" but I could not find any more information about this on the Uni-ball website.
If you want an attractive pen with some unique features, then Uni-ball Fusion could be the pen for you.
Note: These writing samples were written in my new Rhodia #11 pad.