I own a leatherman. Resultantly, I am fairly well qualified to comment on how I find it.
Firstly, small and light it is not. When I first saw a picture, I expected the device to be light, the sort of thing you might slip into a shirt pocket or suchlike. This is not the case; if you want to carry it around, get the belt holder, preferably the leather one.
Second, don't hold any romantic notions that this one tool is better than all others. If the Leatherman screwdriver was better than any dedicated screwdriver on the market, all screwdrivers would be leatherman-shaped. They aren't. In most situations, if you can conveniently get to a dedicated screwdriver, you should. Also, don't bother trying to keep it looking nice and polished and shine, because if you do, you will get very little use out of it.
Third, Usefulness. Like most tools, there are many things it will not do, even if the marketing makes out it can do anything. Some things simply are not practical. You are not going to be able to file/saw/anything your way through the bar of a hardened padlock, if you loose the key. It ain't going to work, man.
Having said that, this is a very good tool. The build quality is very good, and you have to try very hard to break it. If you want a nice thing to get your computer-guy friend, this is an ideal item to go for. I reccommend them.