Don't get too obsessed with CR. It is a guide, not a bible. It is based on opinion, not hard facts.
The FS45 or the GT200R will serve you very well. The Echo is smaller,22.5cc and lighter but still has adequate power. I find it smoother than the Stihl, hence less fatiguing.

+1 about consumer reports and canguys recommendation. I respect what they try to do but for any subject that I have some experience and knowledge of I find their recommendations to fall short. They get some parts right but their recommendations fall more toward the occasional user.

The one area I give them more credence is in their auto reviews. I like their problem history section among others.

I agree with the accessment of Consummer Report. I think they are good for reliability on cars and home appliances. Other stuff be careful. I question there knowledge on a lot of items. I follow their advice on single lens reflex camera, big mistake. I became a photographer and think back how ignorent they were. I bought Magnavox VCR and TV back in early 90s per their advice, were those big mistakes. That time they did not give high marks on Mitsubishi, I have been using Mitsubishi VCR and TV, I have nothing but good things to say about Mitsubishi. I wrote to them on these. They should stay with home appliances and cars.( not high performance cars.) I might take there advice on detergents etc!!!! They need to find experience people of the field to do judging.

With the amount of trimming you must do, I would also look to find a very light trimmer. I believe that the curved ones are normally easier on the back but, of course, not as long. I have an Echo. As already said, CR's "quality" recommendations many times are balanced too lightly against the cost. I like CR for its collection of information, particularly like for autos. But I make my own judgments.