When it comes to doing a general MBA vs an MBA that specialises in a certain field, it is important to weigh up the pros-and-cons of doing each. One of the main things to consider is whether you want to specialise in just one area and therefore potentially limit yourself in others - a general MBA will most likely keep more management options open to you. Having said that, a specialist MBA will potentially make you more attractive to certain management functions of a business.
It is best to do some thorough research before deciding. Therefore get as much advice as you can. Good sources are: prospect universities, others who have studied an MBA, and prospective employers. There are probably a few useful articles on the Internet as well.
Here is a good article I came across from the UK's Independent that looks at general MBAs along side the pros and cons of opting for a specialist MBA.