No his physical peak was clearly 126 pounds. He carried his max power, chin, stamina and speed there. at 140-145 he didn't have the same footspeed, chin or workrate. Look at how easily he walked though Marquez and Barrera at 126 pounds. Look at the unfathomable workrate. He's clearly a more physical opponent there.
Clearly his physical peak was the Barrera fight where he walked through everything and had one of the most incredible displays of workrate ever witnessed in a boxing ring.
any fight he used the most expensive roids he got paid big vs dlh and cotto, but -even though clottey got paid to take a dive- he got paid there and vs limitid, stooopid margacheato, he was a buzzsaw there. once ariza left.... no more elite peds.
In the Cotto fight, Junito was basically training himself so that Cotto was only like 80 percent, still a great win for Pac but somewhat diminished due to Cotto's abysmally horrendous corner in that fight. I'm going to go somewhat against the grain and say that Pac's three performances against Bradley were excellent, as were morales 2 and 3, as was Marquez 4 until the KO.