From what I understand it's Makerbot. That's what I've been told, but I don't know accurate or up to date that is.

ColorFabb is a good filament. In a recent testing comparison of 6 different lines of filament, they scored #2. As you said, it's expensive (more so in the US) and it's difficult for people in the US to get. But again, as you said, shipping would just be too expensive outside of the US. And longer. In the US, we
are able to ship anywhere and get it to the customer within 2 days. That's a big reason people like us.

I've never used RepRapper in either form, but on the testing, they scored very low across the board. Their ABS score the lowest in each category - Ease of Use, Visual Quality, Geometric Accuracy and Impact Resistance. They actually scored slightly better on PLA. They scored #3 right behind ColorFabb in Impact Resistance on both the X/Y and Z axis. However, they both scored far below PLAyPHAb in that category.