The jib is unique because it gives you a dramatic effect, and it also lets you get the camera up high for an uncommon perspective. With the camera up high, you can apply pans and tilts in addition to the crane motion. The bottom line is that you can do a lot with a jib. You even can motorize it for perfectly smooth movement. Motorizing a jib isn't easy, but the effect is fantastic.
One thing to consider with a jib. You'll need counterweights, and even the most compact models are bulkier than a tripod or slider. You're really not going to hike around with a jib, at least not without a friend to help carry some of the load. If you're okay with shooting close to your car, though, it's an outstanding device to have in your arsenal.
Time-Lapse And Motion Control
Kessler CineDrive Control Unit
A few years ago, when time-lapse began to catch on, having the camera locked down on a tripod did the job. It didn't take long for motion time-lapse to raise the bar. To do motion time-lapse, a slider and/or a jib are excellent tools, but to use them for time-lapse, you need to motorize them. You'll need to be sure your hardware can accept a motor, and ideally, you'll want computer-controlled motors that let you vary the speed of the motion. Computer-controlled motion is expensive—more than $1,000 easily—but powerful. If you're not up for spending that kind of money, just go with motors without any computer control.
A lot of photographers shooting time-lapse simulate motion by shooting at full resolution and adding a sort of "Ken Burns Effect" in software after the fact. This actually works quite well since your DSLR's 15-plus-megapixel resolution image can be cropped a lot and still look beautiful on an HDTV. The biggest downside is that you can only crop so much before you run out of frame. Also, many purists will point out that you're throwing away pixels, which you may wish you had later.