This is one of my two favourite Lamy pen models (hint: the other one is not a Lamy 2000), and the one that made me a fan of the brand, even though I had a few Safari and Logo pens before this and wasn't impressed by them. My ‘super pencil’ that writes in fountain pen ink.
It's one of only a few pens that I wouldn't think twice writing with the cap posted; the cap clicks onto the end finial securely, and fit flush so that there is no edge to rest or rub against the skin between thumb and index finger uncomfortably. The pen is also perfectly usable for me without posting the cap.
I bought this originally to fit the ‘50 years of Lamy design’ commemorative notebook, of which I picked up a few heavily discounted. They each came with a Logo M+ ballpoint pen with a rubberised finish that is comfortable to hold and offers superb grip, but I would rather write in the notebook with a fountain pen; yet there are so few that would fit the tight pen loop. After buying the cp1 in matte black finish, which also offers excellent grip, I was so impressed that I've since bought two more, as well as one with platinum finish and a 14K gold nib; but I just don't love the more ‘premium’ version the way I do this pen. I usually use a black Z52 steel EF nib on this pen these days, but I also have a black Z57 gold EF nib on standby, to fit either this or my Studio Lx All Black (SLAB!).