A big headache that comes with replacing laptop power adapters is that the manufacturers don't make universal replacement parts. The usual procedure when it comes to getting a new chord involves looking up the model of your computer, calling where ever it is you bought it from, purchasing the adapter and then waiting for your power adapter to come in the mail or going down to the store to pick it up. Universal laptop power adapters cut out a couple of steps. They are easy to look up and buy online.
The beauty about buying a universal power adapter for your laptop is that when you decide to upgrade to a new laptop, you wont have to worry about having spare incompatible power supply's laying around. You will already have a replacement chord! If you wanted to, you could keep a chord in your car, and one at home. Having a universal power supply will cut down on the wear and tear of future laptops as well!
Another benefit of buying a universal cord is that there are models which are made to accommodate the difference in international sockets. If you have ever done any traveling to a foreign country where there is a difference in power supply, you will understand what an incredible frustration it is to have traveled so far only to have carried a bunch of necessities that are completely useless to you because you cant plug them in anywhere. There are also universal adapters that are made to plug into your car lighter. Adapters that can be used with both DC and AC are pretty common as well. The reason why most of us buy laptops in the first place is because they are portable, it only makes sense to make sure that the power supply we are using is adaptable to many of the different environments we may find ourselves in.