I was looking at larger brushcutters than what I got, and the salesman told me that for my needs, It would be overkill. After using it for two years, I think he was right. My 10 acres is covered with brush, weeds, etc., and I have used it a lot. As long as the saw blades are sharp, I can take down pretty much any tree less than 3" diameter in one swipe. Anything bigger than that, and you want to fell it with a saw anyway. No annual on the planet can stop the 3-bladed grass blade, but I have lacked enough horsepower to drive the nylon line at max speed in extremely thick stuff.
Only you know your needs. I tend to buy more than I think I need (bigger, badder, nastier) and the FS-85 fits my profile. You might use the money you save on at least one extra saw blade, so that you always have a sharp one on the machine.