Part-time MBAs makes sense to an extent- let me explain.

If your goal is to stick to your employer, and possibly move into management then part-time is perfect. This is also the case where they may reimburse part or all of your tuition fees, and you are obliged to stick around for a while. However, if your end goal is to seek employment elsewhere or you've changed your career direction then a standard MBA is called for. For me, the most important aspect of an MBA would be the ability to network, meet potential employers, meet classmates w/ similar aspirations, etc. It may be possible to do part-time for a year and then eventually move into a full time program for the final year.

Questions around a banking career-
I think it really depends on ones interests. High calibre banking is institutionalized- dealing with buying/selling of securities. This means banks dealing with IPOs, hedge funds, fund/money/portolio management, trading, credit risk advisory, issuance of bonds, etc.

Brokerage houses and commercial banks employ financial planners as an incentive to provide financial advice for their retail customers. Here, you're dealing with individuals and their needs- retirement, investments, financing, wills, etc.

As you can see, there is a quite a bit of difference in being a fund mgr vs a financial planner. Really, your success depends on your passion and interest in either of these areas. There is no smoking gun to pinpoint that one is better than the other.