I read a great deal about this some time ago, in terms of 'who would win' in large scale naval battles, the Ming fleets would. Hands down. No question.
At this period of time the only 'European' fleet large enough to pose a threat were the Venetians, but they obviously were not going to venture into the Indian Ocean.
Take for example this Ming treasure ship compared to one of the ships columbus used to sail the ocean blue around the same time;
I think its pretty easy to see who the victor would be. Fair enough the Chinese did not have many of those ships, but they had many more smaller warships and merchant ships that were a great deal larger than comparable European ships. To my knowledge Chinese firearms and cannon were not that much different to their European counterparts and unless a European power sailed a vast armada around the horn of Africa into the Indian Ocean, they would always be outnumbered by the Chinese in a large pitched battle (assuming of course that the ming presence in the Indian Ocean was maintained).
Trade did flourish in this time period, it wasnt just symbolic tributes sent back to China. A great deal of trade did occur and with more time this could have increased exponentially, especially if trade could have been established with the Europeans. The Indian ocean could have become a Chinese controlled transit hub for trade between Europe/Africa and China/Japan/South-East Asia.
I dont think its inconceivable to imagine the Ming fleets establishing secure naval ports along the Indian Ocean as the Europeans would later do to secure their supply routes and have dry-docks for supply and maintenance of the fleets.
Also here's a discussion on another site regarding a similar topic: the Spanish Armada Vs the Zheng He treasure fleet.
http://www.armchairgeneral.com/forum...ad.php?t=91738