I've looked at it before, but finally got around to buying some Harman Direct Positive Paper and tried it out.
Metering is a pain, as it's UV sensitive, so there's a lot of guess work involved, but I've now gotten a couple of reasonable shots out of it:
This was my first successful test, after loading the first 4 with the emulsion facing the wrong way!
It was shot indoors, which filtered most of the UV out, I guess, so despite have bracketed 4 shots and thinking I had it figured out, the next 4 shots were greatly overexposed. (Outdoor shots).
Then I also read that you need to 'pre-flash' it, to get greater dynamic range, so tried that next time and got something functional again:
Absolutely love the look of it and there's a bunch of locations around here (well, within 3 hours drive) that will be perfect for this format.