The greater the difference in income, the more important it is to file jointly.
First of all, you would effectively lose the full value of the Personal Exemption, which is $3,650.
If one person itemizes in MFS, both people must itemize, so you could not get away with you itemizing and his using the standard deduction. If you do not itemize, you would lose his $5,700 Standard Deduction.
The only time MFS is worthwhile, which happened to me twice in many years, is if one of the two, especially if it is the one with the lower income, has very high unreimbursed medical or miscellaneous expenses. Over many years my income averaged about $25K higher than my wife's. One year she had a lot of dental work done and one year she had employment related legal fees; in those two years it was beneficial for us to file separately. In both of these instances due to the floor on medical and miscellaneous deductions we were able to deduct a much greater amount due to the much lower floor on her return than on a joint return. It was interesting to apportion out the remainder of the itemized deductions to keep the combined tax as low as possible.
Mike (CPA Retired)