Samuel Chiltern answered
I think it definitely depends upon your priorities, but I'd say that the biggest disadvantage is portability. Desktop computers can be built to contain a lot more processing power, but for most typical daily tasks, a laptop is more than sufficient.
Portability
It's a lot of hassle to disconnect all the wires, grab the base unit and monitor, and move everything to a new location.
Working on the train is impossible, and sometimes it's nicer to be able to work on the sofa, rather than having to sit at a desk. Also, it's much easier to damage a desktop PC when moving it - as the machine was never designed for it.
Power
Laptops have built-in batteries, and whilst the most powerful machines will consume battery power quickly, they do at least grant you freedom from having to stay close to a power socket for a couple of hours.
Even if your desktop PC is small and portable, you can still only use it where there is a power supply. Plus, if the electricity goes down, your desktop will need an Uninterruptible Power Supply (UPS) to carry on running.
Space
Even a small desktop computer will take up more space than a laptop that you can fold up and put away. Plus, you'll need desk space, and somewhere to put that desk too.
Having said all this, desktop PCs have their advantages. In days gone by, they were much cheaper and more powerful than laptops, although that's not so much the case these days.
The thing I love most about desktop computers is that you can build them yourself and upgrade them much more simply. It's so easy to build a cheap desktop these days, that you can have a home entertainment PC for your living room, for next to nothing.
Portability
It's a lot of hassle to disconnect all the wires, grab the base unit and monitor, and move everything to a new location.
Working on the train is impossible, and sometimes it's nicer to be able to work on the sofa, rather than having to sit at a desk. Also, it's much easier to damage a desktop PC when moving it - as the machine was never designed for it.
Power
Laptops have built-in batteries, and whilst the most powerful machines will consume battery power quickly, they do at least grant you freedom from having to stay close to a power socket for a couple of hours.
Even if your desktop PC is small and portable, you can still only use it where there is a power supply. Plus, if the electricity goes down, your desktop will need an Uninterruptible Power Supply (UPS) to carry on running.
Space
Even a small desktop computer will take up more space than a laptop that you can fold up and put away. Plus, you'll need desk space, and somewhere to put that desk too.
Having said all this, desktop PCs have their advantages. In days gone by, they were much cheaper and more powerful than laptops, although that's not so much the case these days.
The thing I love most about desktop computers is that you can build them yourself and upgrade them much more simply. It's so easy to build a cheap desktop these days, that you can have a home entertainment PC for your living room, for next to nothing.