It's really not a fair comparison. They're both HOF fighters with an exciting style, that's where the comparison ends. One is a great MW in his prime (who somehow started getting a lot of hate as his career unfolded) while the other is a boxing legend who is arguably a Top 10-15 ATG.
Manny is a great fighter but without the PEDs he would have been a great feather weight. The PED era has made things possible that were not considered probable before in boxing. PEDs and the alphabet soup of weight classes and titles. Once again, I like Manny. Fan friendly style. Let's not get carried away though and assign him some super human status compared to other greats. The times he faught in helped make the those accomplishments possible.
Difference , like Apple and Banana. Totally different animal from head to toe. No point of discussion whatsoever. Epic Failed.
Tbh I think the difference is pfp power, speed, résumé, weight transition, versatility, gas tank and punch selection. But that's just me.
Absolutely PEDs was a factor. Pac is a talented guy no doubt. But you are kidding yourself if you think he could have done those things with tighter drug testing and less alphabet soup weight classes and titles in place.
When Manny was moving up in weight and not just beating but obliterating bigger guys with his power, Mayweather called him on it. Manny was doing something not seen in 100 years of boxing. Unfortunately Mayweather was right. Manny is dam good but not superhuman. Manny hemmed and hawed. Looked for excuses not to be tested. Afraid of needles. Afraid the loss of an ounce of blood would make him weak. He finally relented when the public pressure and money offered were too much. We saw what happened in that fight. It was not competitive. Manny without his special helpers suddenly looked like a different guy. Decidedly less muscular, explosive and powerful. He suddenly looked...well...like a blown up feather weight over his head. I was pulling for Manny in that fight but...but what happened was obvious.