IMO, the quality of peruvianus (often reputed to be the strongest Trich, or maybe "on average" the strongest) is all over the place. I have friends, pros in the horticulture world, who would contend that it is actually, on average, of lesser quality than a good pach. Part of the problem I would say is identification....these pach's and peruv's as well as several other supposed species like the cuzcoensis, look very similar to each other and are often mistaken with each other even by professionals....and you have to think, too, that there is some cross-fertilization going on that further complicates things.
That said, when you find a good Trich specimen, and in my experience that has been pach and bridgesii, if you stick to it that should give you almost consistently good results (I am also convinced that good plant food, and control of harvesting conditions can make a big difference.)
I would also say that the bridgesii is easier for most of us to identify with its thinner profile, longer (dark, bacteria-tipped) thorns, and commonly grey-green skin. They can be very strong. The alkaloid profile is to me more acid-like than a smooth-as-silk pachanoi, but then, you don't have to get overly picky about THAT!
WHOA!