Its not that hard to hold a given temp.
What I suspect that he was doing was one of two things, the CPU cold bugged not to far from that, or he didn't want to go colder to show that it fell apart with load handling.
Alum tubes and LN2 do not mix all that well when trying to hold temps. It will transfer the cold very quickly and then blast back to the heat load, or a extremely high swing compared to masive copper pots. The main reason why you don't see any LN2 pots made out of Alum.
Instead they use a copper base and then a Alum tube to save costs and it becomes very hard to machine the inside of the pot when its all one piece with a long tube.
The Koolance Rev2 pot is 3.4" in Dia., thats about the size of the F1 accross its square. It is 6.7" tall vs 5" for the F1. The copper base looks to be about 1.5" - 2" so its not very massive compared to F1 which is about 2.5" of solid copper with the holes in the base part or chamber.
I am not trying to say that it will not work with LN2, it will, but it looks better suited for DICE.
The price point of the Koolance pot is good for some one just starting out with DICE/LN2 and CPU's with warm CB's. It will simply fall apart with no CB AMD chips tho., and I suspect at temps colder than -100c
It would be interesting to see how this pot compares to an F1 with extender tube