Gregor, I guess I expected the mechanics to be the same as Type 55 which I've used a fair bit....what I was wondering about was whether the negs were appreciably different (e.g. more blown out due to the more contrasty nature of the film) or whether they were as good as 55....otherwise why the huge focus on Type 55 as the awesome-ist thing since cherry beer (OK, maybe that's just me) and no mention anywhere of how Type 51 is just as good.
"Faux Collodion" would make a great band name, BTW.
The reason for the huge focus on Type 55 is simple, familiarity. Commercial shooter's are much more familiar with Type 55 because for years it was THEE go to film for checking studio light setups due to the medium contrast instant print. As a result, Type 55 developed a tremendous following and saturated the market place among studio pros and artists.
Type 51 is lesser known since it's primary use was with government agencies and law enforcement. The nice thing is that Type 51 delivers the SAME reusable medium contrast neg. material as 55. The instant print is the only thing that differs, it will be really high contrast and totally useless. The print is intentionally high contrast as it was made to be used forensics people to record fingerprints and crime scene evidence.
But as artists we're after the film anyway so who cares? Simply rate Type 51 at the same ISO as you would for Type 55 and shoot away. Peel and discard the blown out print and voila! You have a Type 55 neg.