"real" 620 rolls, which come with Kodak Tri-X 400 loaded. Justkristin's mom took half the roll, and I took the other half. It turns out the "real" rolls are made out of plastic, not metal like the originals. After the roll was done, I unspooled it and rewound it back onto a 120 spindle .. just to make sure I wouldn't lose my fancy metal one.
The Tri-X film seems to be subtly different from the XP2. I'm not sure exactly how. But I need to shoot another roll and see if I prefer the Tri-X to the Ilford. Unfortunately, my lab sends out the Tri-X for processing, so I have to be extra careful about asking them not to cut the negatives and stuff. I kinda lean back towards preferring the (C-41) Ilford XP2 because the local lab knows me. Either way, fun experiments ahead!