Well, I'm definitely not in the same boat in terms of demographic and work experience (although I'm still in undergrad working on my BBA)--
But I studied for the GMAT, and still bombed it! I'm still baffled at how I got a 510 on the practice test but 390 on the real one.
The test is not a measure of work experience or leadership skills. The only time those things really come in handy is for the writing section in which you can offer some insight based on your work/undergrad experience (for instance, when I had to do the Analysis of an Argument Essay, the writer talked about having employees work in groups as part of a new management strategy. Having been made to do so in classrooms and at jobs before, I wrote about that experience to help prove my point. I got a 5/6 on that section, the only part I did well on!)
I know, this part sounds like reiteration and you've probably heard it from other people and info sessions/guides about the GMAT....but take it from someone who bombed the test: it's NOTHING like how the SAT was, and regular college tests! There's a certain way you have to answer the questions...and all kinds of stupid crap the test makers throw in there to confuse you. And the biggest reason studying for it is important regardless of your education and experience:
EVERY exam is different. Dumbly, I brushed up on my statistics for the test because some classmates of mine said that things we covered in Rudimentary Stats like standard deviation, probability, mutually exclusive events, etc. Guess how many stats questions were on my version? A grand total of 2! What I REALLY should've studied more of was just basic algebra...
I'm not retaking the GMAT until maybe 8-10 months from now, after I've completed my school's math requirement and my last stats course. I think I'll have a better understanding of quantitative methods after that; and that after taking Calculus, the algebra problems I butchered will seem like nothing. That, and I don't have another $250 laying around. I mean, I'm 23, taking 18-20 credits a time at school, and I don't have children but I do have a band to support.
Well, there you have it. Reasons why studying for this torture tool is integral. Hope my rant has proved helpful!