I have both a "normal" laptop and a mini-computer so I have noticed the advantages and disadvantages which, (at least in my opinion), are as follows:
- Small and very portable
- light to carry
- Fits anywhere
- Easy to use
- Surprisingly fast
- Holds a charge for a long time
- Can be too small to do certain projects (such as work or homework) on.
- Generally there is not much storage onboard
- Some do not have USB ports
- No cd/dvd disk drive
- Keyboard can be small for fast typists or those with large fingers.
- The operating system may not be familiar or may be a cut down version of a "normal" operating system.
It really depends on what you want to do on it. It's certainly worth going into a shop and trying one first so that you can see if it is something you could see yourself using.
Better still, if you have a friend who owns one, ask if they would be willing to let you borrow it for a few days so that you can really tell if it suits your needs.