I prefer the slimmer SAK's myself, two to three layers max. You can just slip in into a pocket instead of tying it to yourself with a belt, the actual knife blades on SAK's are better as they are thinner and cut things more easily (which is what a knife is supposed to do), the general public accepts Swiss Army Knives so you will get fewer looks, I believe SAK's are higher quality than the leatherman tools, they are much lighter, they are
much cheaper, and unless you have the need for a large set of pliers often, they can do anything you would use a multi for. If a SAK can't handle it, you should be using real tools.
I carried a Leatherman Wave for about a year or two everyday and switched back to SAK's, I missed how comfortable they were to carry and use, they also cut better being that it is a knife with other tools, instead of a tool with a knife blade. I don't carry anything but a Classic in my pocket and a traditional
slip-joint in the other. Combine those with a flashlight and some ingenuity and thats all I need to get through the day.
My favorite SAK, the Tinker