A very interesting topic..and no right answer.
Two other things to consider:
1. if you did not get an MBA, would your current career path be secure? It may be a mistake to think that your current job/path will stay at status quo (think all the folks in the dot com industry in 2000s or financial services in 2008s). On the other hand, if you work at a small-to-med size business and have a strong trajectory, maybe the MBA is not needed right now and/or can be done in a part time basis.
2. if you know what industry you would like to land in, compare MBA & non-MBA routes there -- there will be individuals that have succeeded via both channels. If a non-MBA alternative appears plausible, it is worth considering.
One variable here -- the MBA does give you flexibility not just coming out of grad school but beyond into your 2nd or 3rd job. While experience matters more at that juncture, the MBA is still sometimes a 'minimum' bar that employers look to.
Good luck!
Aveek Guha, President,
www.mbadaycamp.com