I think the there I less positive aspects of caste system then the negative.
I don't like any caste system. I believe in the philosophy of Sri Bhagavad Gita i.e. Only your Karma makes you big and small. In India even Christians, Sikhs, Muslims etc are somehow having caste system just to enjoy the benefits of government reservation policies for lower castes. P.S. All the other religion people in India belonged to the Hinduism at one point of time. They are all converts.
There are no positive aspects of the caste system - unless you are Brahmin. No one who has visited India would even ask the question.
The positive aspects are impossible to find, (according to 5 hrs of researching for positive aspects) and there are plenty of negative aspects. However, you better ask someone that has first hand experience of the caste system to answer this question.