This pen is a delight to use, but it isn't without flaws. Namely, the price.
The unit featured in this review is the Titanium matte finish, which sells for about $133. That's quite a chunk of change for a ballpoint, and one that I see a lot of people having major heartburn over. Luckily, there are several aluminum versions available as well for the lower price of $68. Still not cheap, but more in line with what most people consider a high-quality novelty pen or the infamous graduation gift. Personally, I have several other pens with unique mechanisms or magnets that cost between $40-$80. I'm not sure this one would make the cut for me. It's simply a bit high, but you cannot ignore the ingenious magnet closure system. It really is brilliant.
While the design of the Kosmos is the selling feature, it also introduces some usability setbacks. For one, it rolls away quite easily since the body is completely round. Also, due to the strong magnets inside the body, it can easily roll away toward a larger metal object (think a metal subframe under a wood top desk) or it can pull small metal objects toward it. This isn't a huge deal, but it has annoyed me.
Another design flaw with the retractable mechanism is that it's incredibly difficult to operate with just one hand. It's possible, but it's awkward. I've dropped it several times trying to open or close it one-handed, and I eventually gave up hope after dropping it a few times.