Although I do agree that Fireline is a more forgiving product, I still find that PowerPro outperforms it.
Fireline has more of a "break-in" period where-as PowerPro is ready to go after getting it wet a couple of times...Fireline remains stiff for a couple of outings
Fireline also gets that frayed-furry appearance as it ages which may also affect it's ability to get you the most distance (every bit of resistance matters, especially with the lighter lures). That furriness must also affect it's strength, it imagine it must be broken strands???
Call me crazy, but I also found that it lit up the bioluminescence more than PowerPro did
...that being said, it's more probable that there just happened to be more light-brite in the water on that night.
PowerPro required more of a learning curve for me than did Fireline, again..Fireline is/was more forgiving to windknots/birdnests.
In the beginning, PowerPro had MANY issues with "phantom breaks". I did some investigating and found that some spools had what appeared to be compressed or pinched spots (best way I can describe it). I believe these were the causes of my "phantom breaks". I did not have any cracked or fractured guides and I had it happen with brand new spoolings of line. I haven't seen this issue in quite a few years now, so I believe the problems been corrected.
Just my 2cents of experience...