While you can use any case in the way that makes sense for you, I don't think this case will work well for gel pens, pencils, or other small diameter pens. Wood case pencils won't fit unless they're about a third used, and other small diameter pens won't stay put, diminishing the value of a case that keeps pens separated while stored. Sure, you can use the pen clip to ensure it won't move, but that adds effort to the process of stowing or removing the pen from the case. In my use, this case fits the purpose of carrying several fountain pens in a stylish, protective fashion.
The Galen Leather Magnetic Flap Five Pen Case is a great case for carrying around a few fountain pens, and it will keep them nice and secure in the process. I love the strong magnetic closure mechanism and the distressed look of the leather material. It's something that I'm sure will last longer than me, and I love the warm hand-made feel that elevates it something more than just an inanimate object. For $74, you can pick up your own case in Crazy Horse Green or any of the other excellent colors that Galen Leather offer.
(Vanness Pens provided this product at a discount to The Pen Addict for review purposes.)