Here is my take in this. The full-time MBA is a somewhat risky choice for you. However, if you don't take risk you don't get a potential reward. I'm in the same boat: lots of years in IT, decent salary. I'm sure you searched for jobs at the higher level such as Director, VP etc and I'm sure you noticed the higher you go the more common is MBA requirement.
Next: FT vs. PT: this is a beat up topic with a little caveat though - Google, Apple, Microsoft and the likes will come to HAAS to hire Full-timers. PT students may not get an access or equal access to those companies. In other words, PT gives you a stamp in resume, knowledge and some alumni connection while FT gives you stamp, knowledge, strong network and the JOB.