Hey guys,
Just my two cents here...
I switched my Muskie line from 80lb Dacron to 80lb Power Pro back around the time it first came out. I had multiple problems with it breaking mid cast, and on sudden hooksets, and other sudden stopages lost more than my fair share of baits, and fish with this line. Now I gave it a chance, but after buying/returning 4 or 5 spools of it, I would never reccomend it to anyone.
I ran through all the troubleshooting (eg. checking my rod guides, visually inspecting the line for frays, nicks, or any discolouration, etc.) However, I haven't used it in years, so, I'm not sure if they've improved thier line or not.
I will say though, that from my personal experience, Power Pro was very strong if you were applying even tension to the line, (eg. pulling in large sticks, attempting to bend hooks out on snags, etc.) but where I think it really fails as a line is where the line is suddenly stopped, and a great amount of force is applyed quickly, as in setting the hook on a large fish.