I have the Camillus and Wenger Standard Issue and Victorinox Soldier, in my experience the Camillus holds an edge a little bit better but I prefer the SAKs because of much better fit and finish (and looks), I have tweaked the Camillus a bit to make it to my liking, basically filing down the kick of the main blade to lower it a bit when closed.
Some comparisons:
Camillus is tough and roughly finished, all steel, has a good long shackle, can opener is typical "beak" style, quality control not as consistent as SAKs, main blade not flat ground but has a little bit of hollow.
SAKs are tough but more finely finished, with aluminum scales, they have extremely consistent quality, can opener style includes a screwdriver tip for small flat screws and in a pinch will fit Phillips, Wenger has a shackle, Victorinox can be found with or without small keyring.
There are, of course other alternatives, such as Camillus boy scout knives or the other SAKs, I usually carry a Vic Huntsman along with my Schrade stockman.
My favorite in this style is the Victorinox Farmer which adds a saw (rev, you probably remember I was looking for this one some time ago, got it now).
Luis