Yes, bongso is now the correct species designation, but I prefered it the other way, where you could actually tell which plant you were getting.
Here is a pic of the hybrid in question, carunculata var. robusta x truncata
5" pitcher on a 4" leaf
The other plants I saw had black pitchers with a smaller, more horizontal peristome. Kinda hard to say what color mine will become as this pitcher may have opened in transit and my normally black bongso isn't looking so black in my current winter conditions.
Last summer This winter
The pitcher on the left is actually not dead or dying and the one on the right is newly opened. Above pitcher is probably as dark as it will get.
The pitcher in the middle is dead.
And just for contrast here is what was formerly called carunculata:
Showing the color progression. Never as dark or peristome as pronounced as bongso, but I think the carunculata var. robusta has the nicest form/color of the three, more like the bongso above, than the carunculata.
It will be very interesting to see how this hybrid matures. I would definitely get one if I were you, and probably even two, as I should be getting another one soon.