Stihl FS90R is probly the best trimmer on the market for the price (around 300)
I have used almost everything except kawasaki. The stihl will outlast everything available, you can't break them. Solid shaft, super efficient 4 mix, they are almost bulletproof.
My stihl handtools are super durable, extremely efficient, super powerful, and that's what I look for in handheld's!