I hear a lot of anecdotal stories but tend to believe what I see myself.
I've got several Poulans that are 4-5 years old and never had to replace the primer bulbs yet. I DID have to the replace the gas cap on one that swelled up so bad I needed a wrench to turn it.
We've got 10% ethanol here and I haven't noticed any difference in anything in regard to rubber-rot. When I worked for Sthil dealer - we had rubber fuel lines rotting out something awful on Stihl pro-saws 30 years ago. So, I don't blame it just on the fuel.
The saws sold as Poulan now have nothing to do with the original Poulan saw company in Louisiana. The newer Poulans are made by the same company that makes Husqvarna. The difference seems to be that Husqvarna still makes some pro saws with metal crankcases (instead of plastic). Poulan does not make any professional saws.
I buy Poulans as "throw-away" junkers that I won't feel too bad over if one gets stolen. For that - they've been fine. I DID buy a 20" Poulan at Home Depot a year or so ago with a "tool-less" chain adjuster that was just plain awful! What a piece of cr*p! I finally drilled a second hole in the bar cover so I could fasten the bar with two nuts instead and it's been fine ever since.
Now adays - if I wanted a good pro saw - I'd stick with a Dolmar/Makita or an Efco. I find them to be much more saw for the money then anything Sthil has.