After a lot of research, I bought a corded-electric Black+Decker PP610 pole saw last year. The reviews were good, the saw is slender, it's more powerful than some (at 6.5A), and it has a 10-inch bar.
I'm not a professional, but I spent weeks cutting down 300' of old laurel that had grown 25 feet high! Lots of time, lots of cuts. The saw didn't bog down, even on the 8-inch trunks.
One of my concerns buying it was that the saw couldn't disconnect from the pole. I wanted to be able to chop the wood into pieces once it was on the ground. But it turns out that the pole is very nice for that! If you retract the pole, it's just the right length to stand there and cut felled branches without having to bend over :)
I like the electric aspect because there's no fussing with an engine, no gas to mix, etc. Just take it off the wall, plug it in, and it goes.
Oh, and as @Harper stated, don't cheap out on the extension cords. Look for something at least #12AWG. I found some #10AWG (which is bigger than #12) at Costco last year for less than the #12's cost at home improvement stores.
By the way, I bought this saw from Home Depot, but it looks like they don't have it any more. My link (above) is to Amazon, and is cheaper than I paid at the Home Depot.