Pyrocat is preferred by many current workers over pyrogagallol (pyrogallic acid) for several reasons.
1. somewhat less toxic although gloves should be worn with both.
2. The stain is less intense, but a part of the spectrum which provides for more contrast in the print.
3. The stain masks the grain of the film.
4. the printing time is usually shorter than for pyrogallol negatives.
5. Both forms of pyro tan the emulsion providing more protection from scratches.
6. Separation in the highlights is superb when compared to MQ or PQ developers
7. It is probably the cheapest developer around when diluted to working dilutions.
8. if mixed in polyethylene glycol, which it should be, it lasts for an extreme length of time. I have never had any go bad.
9. the scale of the negative is enhanced because the film curves don't have unusual fluctations.
10. since the concentrates are liquids, it is quick to get ready for use.
I can go on, but this should be enough. By the way,I have spent considerable time over the past 70 years working with various develoers and currently still maintain solutions of four different pyro develpers. Pyrocat HD+ is my absolute favorite.
Agree 100% with what Jim says, I've tried a lot of developers over the last 50 years and it's the best alround developer I've found, consistenly excellent results and negatives that are remarkably easy to print.