I purchased two of these pens, one for me and one for my wife. It is very modern to say the least. The design is odd but very nice.
It has an XS or fine nib that is steel. It is smoother than a Parker Vector fine point, that is my only other fine nib. It is stiff and writes very smooth and wet. It lays down a nice even line and the Rotring blue black ink does not feather on standard 5star paper.
The grip is unusual to say the least however it is better than any other pen I have used once you get used to it. It is very well balanced unposted. When posted it is too top heavy for my liking, this is due in part to the somewhat large metal slug in the top of the cap.
That is all I have for now, I suggest this pen to anyone who wants a nice writing inexpensive pen!
***Edit*** This pens also ejects the cartridge when you unscrew the nib section, now thats nifty! Also the cap snaps on to the pen when posted, no chance of it falling off.