Enzy,
All three will do the job of camp kukri with the CAK edging ahead in the heavy chopping department. None of the other two can hope to keep up with a CAK in a heavy chopping environment. That is what the CAK lives for. Now when it comes to smaller camp duties, the CAK will feel like you are spreading peanut butter with a surfboard.
But when the discussion turns to being used as a fighter, the M43 will edge far ahead of the other two. The CAK simply cannot be considered a fighting weapon because of its size, balance and weight; to a lesser degree this could even be said of the WWII, with most of them showing up with 1/2" spines. My newer Santosh WWII has a spine width slightly fatter than my newly acquired 22" Ganga Ram! I don't care how big or strong you are, the current WWII's cannot be considered "nimble" in the fighting role by any stretch of the imagination.
The M43 also edges ahead of the other two when it comes to smaller camp tasks. The lighter weight, less curved spine, flatter belly and thinner blade make it easier to do cutting and slicing tasks. It would be even better in this role if they used the technically correct M43 bevel. (note: this does not apply to the boomerang style M43's popping up lately) The CAK and WWII are like wedges and do not do smaller tasks well at all, especially slicing. (keep in mind I am not talking about WWII models made 4-5 years ago, I am talking about the ones currently available)
So in my opinion, for the best pure chopper the edge goes to the CAK hands down. This is especially true in the car (vehicle assisted) camping scenario where you don't have to hump it in. In the fighting role and probably as the best "all around" kukri of the three, the edge goes to the M43.