Even with the Xport, which is transfering directly to your 360 HD, you have to open the #3 partition, where the old Xbox game saves are going to be stored.
Otherwise, the Xbox1 game saves are not recognized by the 360 HD. They won't be by the 360 memory cards at all.
Confused? Me too, and I actually got my updated rosters and my old 2K5 profile transfered over to my 360!
I think a lot of people are going to be frustrated. The good news, you get 2K5 on the 360. The bad news, you have to jump through even MORE hoops, and buy more equipment, to get it updated.