What are your thoughts on MBA for middle level manager?

I’m in middle manager, in Fortune 500 company, leading of diverse team of 40 employees, I have engineering background, have been in the role of 3 years and in the industry for 16. I’m married with 2 kids 9 and 6. I currently live in MCOL area. I recently came across an initiative that my company is collaborating with state university and provide an opportunity to offer online MBA. It will take 2 years to complete and probably covered at 100 percent or so. I have already have graduate degree in engineering but it hasn’t helped me in my career. MBA is good to add in your resume but don’t know it will be creating any opportunity for me within the company. On the other hand, I’m thinking that it will provide me some opportunity to learn and grown but I’m not sure working in online environment, how much it will help. Has anyone done went for higher educations (MBA) in your 40’s? What are your thoughts or what would you do in this scenario?