The field of electrical engineering is vast. It covers everything from power generation to the production of billions of transistors in inch-thick chips. A BTech in electrical does not mean you are an expert in one field. You can take courses in all aspects of the subject, and choose electives. If one is a MTech, he specializes within a particular field such as communication or microelectronics. If he wants to continue his core engineering, this can be a benefit.
Advantage: Having a specialization allows him to gain more attention from his employer.
It is always better to be “Master Of One (/two),” than being “Master of None” and “King of All Trades.”
Take note: You must master the area in which your passion lies. ;p