I have both Echo and Stihl.  Both are excellent saws, but for me, I like Echo better because of how much easier they are to start, and for the money, you get more saw, or for the same size/power, you spend less for Echo.  
Both my Echo and Stihl saws came from the same dealer. I also bought my Scag mower from him too.  I've spent a fair amount of money there, and so have a lot of other people.  He recomends Echo over Stihl, but wil sell you either.
I can't comment on the other brands except to say that I went the route of buying Husqvarna first and hating it. Hard to start and it didn't last very long.  It might have been a dud, because I know others who have had much better luck then I did.  After that I went with Poulon Pro.  I figured I'd go disposable and just get another one when that one burned up. It ran good and had plenty of power, but after sitting for a few months, it was a nightmare to get to start again.  
I bought Stihl after that.  I like Stihl, but when I went in to buy my weedeater, my dealer talked me into the Echo instead.  More power, bigger gear head for the same money compared to Stihl. When I went back to buy a pole saw, he did the same thing. He showed me the Stihl model and the Echo.  It was a big difference for the money, and I went with Echo.  I'm very impressed with Echo.   There is a HUGE difference in how easy it is to start. 
I don't think anybody who buys Stihl will regret it, but if you had one of each, I know that you will grab the Echo before the Stihl.
Eddie