From my point of view, your career does not need to get any better to make you more competitive for even top five MBA. You got solid experience and looks like you will get solid GMAT, in both cases you are well positioned for applying to pretty much any MBA program. What you do need is a reason to get an MBA: you are doing very well as a businessman already, so why do you need an MBA? You are the kind of applicant who has a great record but needs to differentiate themselves from too many people who also have a great record, in order to stand out and get accepted. To get yourself into top-tier business school, you need to come up with a unique personal brand. For that, you need to show special interests, and that means you definitely need to work on your EC. Start early because if you start EC one or even two years before applying to b-school it might look like you did it just for application purposes. Also, though your internship sounds great it wouldn't really count towards your official pre-MBA work experience track record, which is on average 4 to 5 years for business schools. To sum up, your main task as an MBA applicant wouldn't be to go from great to even better work experience (though doing that certainly wont hurt your chances), but to work on differentiating yourself from an excess of people with similar work profile competing for top-tier MBA schools.
>>>>>>> "Fences set on a high place will not stand firm against the wind; so a timid mind with a fool's resolve will not stand firm against any fear." ~~~~~~