I also have a 6339 in my pocket today.
I have a couple of Case Sowbellies. Both in CV. I started with a 3339 in yellow Delrin. I liked it so much that I just added a 6339 in chestnut bone. (I think there is only one other design which I liked so much that I have purchased a second to get a different cover option.) I particularly like that the nail nicks on the sheepsfoot and clip are on the same side so that I can open all three blades using my standard opening method. The sheepsfoot is my most used blade and I really appreciate this feature. I have not seen this in any other company's interpretation of the sowbelly design. And I understand that not all Case Sowbellies have this.
As usual I agree with Jeff's observations. The Case Sowbelly carries like a smaller knife in the pocket. I think because of its rounded bolsters and it's slightly thinner width. But out of the pocket it's a perfect size for weekend chores.
Here's my 6339:
Here's my 3339