I find the Calypso Jr. much larger than the Delica. The integrated choil and carved out finger grooves really give it the leg up. In fact, just this friday, I went down to the store and held both in my hands, deliberating whether to get a caly jr. or a delica (3) or a minigrip. I walked out with the caly jr. and minigrip. The lack of a choil on the delica hurts it in my opinion. It's far behind the caly jr., which is discontinued...
The minigrip is a strange beast. I actually really regret buying it since I don't want to start a collection. It's a very sturdy knife and the balance is just right for me. I've read people saying that the handle is lighter than the blade and it feels cheap, but on the minigrip, the balance is between your index and middle fingers, so it's pretty far back on to the grip. There's also as little flex as I've seen in any non metal alloy scaled folder. However, the lack of a finger choil means it isn't ideal for the most delicate of work, thereby creating something of a contradiction. It's a beefcake knife in mini form. This may be good for your camping purposes.
The caly jr. is a user knife. It's also the sharpest knife I've got, even out of the box. If I could only have one between the minigrip and the caly jr., I'd easily go for the caly jr. for its full four fingered grip. The minigrip is really a 3.5 finger grip at best unless you have small hands. If the absolute strength of the knife matters to you, I suppose you could still balance your choice between the new delica and the minigrip. The minigrip is probably heavier than the delica, which may hurt it since it plays a backup role, but otherwise it seems to be a toss up. As a knife I'd want to use, I'd go for the caly jr. For a knife to abuse, I'd go for the minigrip except that it really begs for another half inch in the handle so that you can properly abuse it.