just got back and a "heads up" to anyone with nexus. There is no GLOBAL entry benefit at BUF. There is a TSA pre-check line, but it has to say TSA pre-check on your boarding pass (ours didn't). I googled MCO and global entry, and there were supposedly GLOBAL ENTRY kiosks at MCO. But we didn't find this, only the TSA pre-check line. We tried showing our nexus cards, but they wanted TSA pre-check on the boarding pass.
I was really disappointed with this as I made the effort to call SW before our trip and make sure that they had our nexus numbers. When we got home, I called SW again, and was told that all they do is put it in our profile. What we need to do is put the information in when the travel is BOOKED. Now she also told me, for the future, that if we did not see TSA pre-check on our boarding pass, if we had called them, they could have added it and would appear on a reprint of the boarding pass.
lesson learned.