I was recently offered a job at another firm. When I gave notice to my employer I was made a counteroffer to stay. I accepted the counteroffer, choosing to remain with my employer.

I am now having second thoughts and am considering job hunting again. However, my employer has already financially rewarded me for staying with the firm. Is it ethical to accept that reward, then turn around and leave for another job? When I was given the financial incentives to stay with my employer I signed no contracts or legal documents, so I don't believe I am "legally bound" to remain here, but I have some ethcial concerns about taking extra money for staying, then leaving a few months later.

What to do?