I have experience with Stihl, Poulan, and Homelite (yes, Homelite).
I used the Stihl when I worked for the county Parks and Req dept for a variety of tasks, it always worked well and never gave me any trouble. My small amount of experience with Poulan is limited to cutting up firewood at camp. The one in question worked well once you got it started, but it was a bit ornery in that respect.
I have the most experience with my dad's Homelite saw. It wasn't very big, but between the two of us, it has cut down and cut up a couple hundred trees ranging from 2" to 12" in diameter. I've run it all day long clearing brush and trees at my grandmother's, only shutting it down to fill the tank, sharpen the chain, to eat lunch, etc. There, we were cutting pine, various hardwoods, and 50yo Rhodedendron bushes standing 8ft tall with 12" trunks. My dad used it to harvest timber on a plot in the National Forest. Every day, he'd cut down a few trees, limb them, cut them to 6ft lengths, and bring a load home in his pickup. Once at home, he'd use the same saw to cut them to splitting length. It's only weakness IMO was the itty bitty nut used to hold the bar in place. I just didn't feel comfortable really torquing it down. Otherwise, it ran like a champ and never let us down.
If the price were right, I'd buy another Homelite, but my first choice would be Stihl because they are good saws and service would't be an issue.
Chris