Yoyojack,
The UPSC is a completely different animal.
Unless, you've crossed the age limit or have run out of attempts, I would recommend staying with the UPSC.
People in my family prefer clearing the UPSC over attending Harvard. So, for them even Harvard is a plan B! I'm a black sheep among them since I am neither an officer nor in Harvard
UPSC over Harvard! Why?
The reason is simple, IF you clear the UPSC test, you live an elitist's life and make an impact (if you really want to). A politician may go out of office after the next election, but if you've cleared the UPSC test, you spend at least 30 years at the top. There are state specific tests too that have more lenient age limits.
Don't give yourself any backups, you'll fail in both(UPSC & GMAT) that way. Stick with one. Of course, if you need a job to sustain yourself, get a job. But, goal-wise, stick to UPSC.