I went, I saw, I froze my fingers. Dual was indeed duel, and multi-format means no division between machine types or rider categories. So you had roadies, fixies, bmx, mtb, trials, men, women, locals, pros all riding together. The roadies proved to do best but the fixies also put up a good show and one bmx rider came within feet of beating a roadie. There were 16 "invited professionals" and 16 "local heroes" but the top three were all local - well, it is a hilly place.
It wasn't the whole length (height?) of Park St but about 3/4 of it, with two bottlenecks. These gave the bmx guys an advantage as they were fastest out of the gate and cold block their opponent. Usually not enough of an advantage to sustain their lead to the top though.