Yes, using the pen blade on the Whaler has to be well thought out, but it can be useful. My Whaler with its 2 blades is thinner than my single bladed Roughneck, not by much, but it is thinner. They aren't exactly unobtrusive in the pocket, but not nearly as bad as I first imagined.
If I remember, when I get home from work Monday, I'll try and get a comparison pic with my GEC made Schrade in the 23 and 73 pattern, as well as some others so as to give a sense of scale.
They fascinated me as well, but I like them more than I figured I would.