Arm 7/6 or conventional 30 years now?

If you can shave the interest rate little bit (0.5%), would you consider Arm 7/6 instead of conventional loan?

Edit to add details: It’s on a $1.4 million loan. The difference is 230$ per month. Annual cost of about 2800 difference. It should cover the refinance cost in a couple of years. But the question is, would the rates for sure drop at some point during the next 7 years?!