It is kinda small for my yard (over an acre) but it works well. I have not had to replace the string yet so I can't tell you about that. It is light weight and easy to use. It will take down very tough weeds and tall grasses but you can only swing it a few feet in each direction and it has to be pointed straight down for good coverage (You can't hold it on any kind of angle or it won't work well).
I have had a BUNCH of string timmers and I always have problems putting in more string...or getting the string to come out. I frequently had to take the head apart and pull the string out manually.
But not with this string trimmer! It works great. I really like the wire guide for edging! I have no complaints with this string trimmer!
I hate grass. Most of my yard is vine and ground cover. Mowing would just screw things up, so I use a trimmer to bet rid of the tall stuff and encourage the ground cover I like.
The Grass Hog was great for the first year. It's light and powerful. I love how it doesn't get hot like gas trimmers do. Obviously, it starts the first time, even at the beginning of the summer.
There was a safety recall on my model, which isn't an issue on new models. I would write nothing but glowing reviews except the motor tore up the belt, making my trimmer totally useless. This damage happened about a year after purchase. It is still under warranty, but the warranty centers are all hours away from my house.