Hello Oolie, and thanks for the confirmation.
Naturally I did note the thread date, but as there are references by some at the beginning to having tasted the OS variety, it was unclear to me if this is a brand new hybrid, or merely one that has caught on in popularity recently. As I did see the name "Zill" pop up throughout this thread, I did a google search on it this weekend, found a phone number in Boynton Beach, and had a nice conversation with an amiable gentleman named Walter Zill--we talked about mango trees for a good 20 minutes.
I asked Mr Zill if the OS variety will grow into a 50ft behemoth of a tree if left to its own devices, to which he replied, "they all will, eventually."
Be that as it may, I'm going to attempt to shoehorn this 6ft/7gal Orange Sherbet into the limited space I have remaining on my already well-planted property, and try to keep on top of the pruning, as suggested here. I'm intrigued by this one, and for $45, it was reasonable.