I guess it's time for somebody who actually uses one to speak up. I don't know about this "ultimate" business, but I'm willing to send a little love the Swiss Army Knife's way. "Jack of all trades, master of none"? Maybe so, but for what I can get in my pocket it ain't bad. Take for instance the "Farmer" model I had in my pocket yesterday-- I opened a can and a bottle with it, opened the mail, tightened a couple of loose screws, pried some pistachios open with the can opener, made a new hole in my belt, started a couple of screw holes, and sawed some sheetrock out so I could get some conduit through. That's just what comes to mind right away. I had access to a purpose-made tool for most of that, but the Swiss Army Knife was right there with me and I knew it'd do the job plenty well enough. For cutting that sheetrock it was the best thing I could use, because of the limited space. Now with a nice lockback single blade knife, you better stick to opening the mail. I make adapters for 1/4" hex screwdriver bits that'll fit on a Swiss Army Knife's cap lifter, or even on a straight screwdriver, and with one of those, I can drive any kind of screw with my Swiss Army Knife. Leathermans and such are nice, too, but I can stick a real pair of pliers like, depending on what I'm up to, a small pair of dikes, some little slip joints or even a Channellock 426 in my pocket with a Swiss Army Knife and there you are, Bob's your uncle.
Now if you start talking about one with scissors, or pliers, or a magnifying glass, or any of the other I-don't-know-how-many tools they can have, it can sure make a plain old pocket knife look anemic. I wouldn't want to skin an elk with one, but elk-skinning ain't on my everyday to-do list, either. I'd hate to know I had to go through the day without one handy.