Margin Loan

What are the tax advantages of having a margin loan? I currently have a margin balance of $30,000 and pay about $220 a month in interest. Since my dividend income exceeds that annually, I deduct the margin interest on my taxes.The majority of the dividend income is reinvested but the remainder goes toward paying down the margin loan.

Is it better to carry a zero margin balance and bank the dividend income or should I carry on using it as a deduction?