We are often asked "If I buy your equipment, what pointing accuracy can I achieve?" It's a difficult question, because while we sell attitude sensors and actuators we do not sell complete ACS solution engineering.
The University of Toronto Space Flight Laboratory has just published a paper (here) on the results of the BRITE constellation. Using an ST-16 star tracker and three RW-0.03 reaction wheels they achieve 12 arc-second 1-sigma pointing error as measured by their payload telescope. The BRITE satellites are 7 kg 20x20x20 cm cubes, and can be thought of as equivalent to 8U Cubesats.
This is by far the best pointing performance ever achieved by a nanosat, and we congratulate SFL on the accomplishment.