What factors should I consider when deciding between a general MBA vs. a specialized MBA?

Because you already have real world experience in IT but are unsure it is where you want to stay, a general MBA should be fine.

If you want to stay in IT, what most companies care about is actual experience - and it seems you have that. Having an MBA and experience in IT is a great combination and having experience in IT is far more useful than having a specialist MBA in IT.

Another issue is that IT management is usually not a challenging place to get to if you are interested. I've worked with quite a few people in IT and it was the rare one who wanted to be in management. Most wanted to keep their hands in the technology. For this reason, IT management is different from many other fields in business.