I think after you have green card, they will track down you for exit tax as citizen on tax.

One difference is if you marry a non U.S. woman. then you need to put her on waiting list for 5 years before she can come to U.S. because you are only a permanent resident. But since you have paid millions of taxes. I guess you are rich enough if this happens to do things in alternative way such as EB-5 for her.