Well, there are several things to consider.
Netbooks are very small, often with 12" or less screens and keyboards that have small keys to save space - these may lead to wasted time and added frustration while looking at diagrams or typing papers. In addition, netbooks are not very computationally powerful. If your area of study involves the use of powerful programs (CAD, extensive programming, MATLAB, Maya, Vegas, etc.) you may want a more powerful computer to show for it. However, they are light and easy to carry around, as opposed to regular notebooks, which can range from somewhat small and light (14" or so at 4 pounds) to very large and heavy (18" and more than 10 pounds). However, regular notebooks add in nicities such as larger resolution screens and spacious keyboards (sometimes even with a number pad - necessary if you work with numbers excessively), and also offer beefier hardware that can do more. These, of course, are at the expensive of size, weight, and (sometimes) battery life.