I've used the Harman DPP in a Bronica ETRS, cut down to 6x4.5cm size, preflashed, similar to Kerne's experience. Good results, especially given the electronic shutter on the ETRS goes up to 2 seconds, much more accurate at these speeds than a mechanical shutter on an LF.

The kinds of subject matter that work well in these small sizes are portraits and still lifes where the principle subject matter is predominately one central object.

I like to use indirect north-facing daylight for the Harman paper, metered using a handheld meter at ISO1.6.