CPAin14: Well in public accounting I can't really speak to it because I've never been; so my thoughts below refer strictly to corporate finance/accounting, and mostly Fortune 500+ level. From an entry level perspective, neither one holds much value. You will be doing spreadsheets and grunt work, the company really doesn't care what you learned in your MBA or CPA program, they will do things the way they do and really don't want to hear an opinion from somebody who has zero experience. Your job as an entry level is to do the job, plain and simple.
Once you progress into that 3-5 year experience range is where you really need to make the decision. I would say, if your job is more formal, technical accounting (GL, AP, AR, recons and close) the CPA is what you should get first. It will help you quicker if you want to progress to a Controller type role. However, if your plan is move into Cost Accounting or Finance, communication becomes KEY. You must understand how to communicate to people who are mostly far from numbers people and are scared of Excel. What the MBA did for me is give me communication perspective. If you actually put something into a decent MBA program, you will get a lot out. Combined with experience, the MBA can become powerful indeed. Can somebody who is book smart enough sleep through it and still get the degree? Sure. But they will be immediately pinned as an imposter and they just won't go very far. A top school might get them two or three opportunities, but even then if they aren't the real deal the opportunities will dry up and middle management is mostly where these people stay. FYI, some people can sleep through a CPA program too, forget the information as quickly as they memorized it, and the same thing will happen to them if they don't know how to APPLY the information learned in a CPA program.
Once you hit the 10 year point you should be on the Director role. If those of you who took the controller route wish to go no further, you can probably get by with just a CPA but there will be others with both an MBA and CPA and companies will take them over you if all else is equal. Here is the tricky part I didn't figure out until a couple of years back. Once you become a Director/VP of Finance, especially if it's a smaller type company where you will oversee both accounting and finance, not having a CPA will limit you severely. Companies like you to know what you oversee, even (and especially so) if you have a strong controller. I didn't get this ten years ago but I get it now.
At the end of the day, if you really want to progress to a top Finance person, whatever that is on the level of company you are focusing on (Director for small, VP for medium, CFO for large), you will absolutely need both. However, neither will help you very much without the experience. So I say, to all you whippesnappers taking the corporate route, slow down! Focus on learning whatever you can both at work, and while you progress through your CPA/MBA programs.