If you are talking about DC-DC converters, It all depends on the output current you require. If you use a transformer, you can have a higher current output for a smaller circuit. The alternative is a stack of maxim chip circuits, especially if you are looking at greater than 6A on the 12V line. While the maxim circuits are easier to build, some of the parts are becomming increasingly harder to find for free. The maxim chips are also expensive if you actually buy them. So that is another thing to think about.Originally Posted by d4lions
As far as noise is concerned, If you build a transformer based setup with the correct filtering and board design, you shouldn't have a problem with noise. That's what all your home audio and computers use, so why should it be any different in a car?
Anyway, hope that answered some of your questions.
* woohoo - 100th post