You would think I would know better after all I've read on Lawnsite, but two weeks ago I bought a 4 stroke Troy-Bilt trimmer. I liked the features, and the fact it was a 4 stroke, and I liked the price ($225). I don't do a lot of commercial trimming, but I stumbled onto a job cutting 6-8 foot high elephant grass on rough terrain. I put the brush blade on my Troy-Bilt and got to work. About 45 minutes before completing the job, my trimmer ground to a halt. The engine had seized. Now I realize that the trimmer was not a commercial grade trimmer, but still should have been able to stand up to heavy use. I took the P.O.S. back where I got it and got my refund, and after much deliberation bought a Stihl FS85 split shaft trimmer. It's lighter, more powerful and from what I've read will stand up to anything I can dish out. Moral of my story, you get what you pay for, and if you ever plan on using a piece of equipment on a job, get the best you can find. Some of us are slow learners.