My father-in-law has a big wheel walk behind that kicks butt since he got the rope looking plastic, sorta like 3 strings woven together.
If your budget calls for a string trimmer, I just did a lot of research. All the 31cc 2 cycle motors are the same, made in china. MTD owns anything from Bolens, Troy-bilt, Yard Machines, Yard Man, Ryobi, etc. I paid $90 bucks for the Bolens 150 vs. 150 for Ryobi or Troybilt, which advertizes as trimmer/brush cutter, it is only a small 8 in blade you have to take the head off and attach. The trimmer has the removable shaft for mounting other options, but they are overpriced. The switchable shaft also adds too much weight. Bolens straight shaft, 10#. Others with removable shafts, 14#. Echo is highly regarded and you will notice that most yard groomers will have them on the trucks. Stihl and Husqvarna are also highly regarded, but overpriced. I was shocked at the price of the Husqvarna; I got a chain saw that was reasonable, ordered from an outfit in Co., $100 less than Lowes. I just cant go $300 for a string trimmer.