Quote from gmst:
Grass "looks" always greener on the other side. 
I want you to seriously answer this: A 2 year MBA will set you back by 150k in tuition and living. Plus, assuming your opportunity cost at 100k per year (salary and bonus combined) would set you back by a combined total of 350k. Meanwhile, if you put 2 years in your current firm, you might get a promotion. This is all assuming you are a beginner, hardly profitable trader. If you are a successful trader and continue to make solid money, your bonus could be upwards of 200k. That completely changes the equation.
Compare this to doing an MBA. What will it give you? Yes, you will get some contacts, you will get to know people, but so what. You will have to spend a lot of time on courses not directly of interest to you like HR, Marketing, Strategy etc. etc.
Please answer this:
Instead of doing an MBA, why not put all your effort at your current firm and try to become a super star trader earning millions. Of course, with the kind of firm you mentioned, a million is completely reasonable to expect if you are a solid trader.
You raise some very valid points, so I will address them.
First, although it's theoretically possible for a superstar trader at a top prop shop to make seven-figures, those days of huge bonuses are pretty much gone. I mean I have friends who worked at these shops and made a killing during the "easy" money days of 2008 and are now semi-retired. Prop trading landscape has shifted significantly since then. With lower volume and vol, more regulations, etc., I'm not quite sure that we will see those days again. I'm pretty confident that at my firm the only ones making seven-figures are the owners. Heck, look at GETCO's financials when they bought knight, and it's obvious how much profit margins has shrunk in the last few years.
Second, there are indeed a lot of classes in b-school that will not be directly related to my core interest, but I don't mind getting a broad general management education. Moreover, there is a big difference in curriculum and course offerings between the likes of wharton/booth/mit on one hand and say hbs/kellogg/tuck on the other. The latter are focused on consulting, general management, corporate strategy so have few interesting finance courses. The former, however, have a lot of upper level finance courses I can choose from, so academically I would be more than satisfied.
Third, I agree that the short-term costs of doing an MBA is well into the six figures. With high tuition and cost of living, it's definitely a big sacrifice. However, I remain convinced that a top 6-7 program is worth it given my professional goals. If you wish to make a career transition, an MBA is probably the best way to go about so, especiall for fields such as banking, buyside, consulting. Given that my core interests are aligned with investment management rather than trading, that is a sacrifice I'm willing to make. And long-term wise empirical studies have shown that a top MBA is always worth it. I have yet to meet a student or alum of these programs who regret attending. To put it bluntly, even if I were making say $500K/year as a trader, I would gladly leave that to go to b-school at say harvard, stanford, wharton, booth.