ballad wroteI suggest that you get a macbook pro
new 13" retinas are for about 1500$ and are very well built, with a 9 hours battery, 13secs boot up time.
and think about them as an investment because you will sell them in the future for 70%-50% of the original price, whereas the hp or toshiba or lenovo are most likely to fail in the future and if they don't fail you will sell them for 200$.
If you are talking about engineering, then never go with Mac. Engineers like Windows and Linux, Mac is for Designers.
Go with Core i7 and 6 GB Ram and it's better to be equipped with SSD Hard Drive.