I have spied the Rotring Core Eternium Rollerball for sale on several pen sites over the past year or two, and I finally bit the bullet and ordered one from Goldspot Pens when I ordered my Fisher Space Pen. I don't think the design is for everyone (that's probably why it was marked down), but I thought it was pretty cool and interesting looking, so on its way to me it came.
While I like the design of the pen, I could tell the real issue with it pretty early on. The barrel is made from plastic and a very lightweight aluminum, but as you can probably tell from the picture, the cap is very large, and unfortunately a little too heavy for the rest of the pen. With the cap posted, the pen was off balance. I even felt sometimes that is was going to flip over the back of my hand while writing if I wasn't careful. It was a very odd feeling. With the cap unposted, the barrel is almost too light to write with. I don't necessarily mind a light barrel, but I prefer the pen skinnier if it is.
The ink cartridge wasn't especially impressive either, but that didn't bother me because I was planning on switching it out very soon anyway. I may hold off for now unless I get more used to writing with it. This is one of those pens that may require some time to break in and get comfortable with.
Click here for the XL review.