I am in the market for a new trimmer....Homeowner with an acre to cut. Use the trimmer mainly in the ditch along the road. My old trimmers have finally bit the dust. I have noticed they now have 4 stroke trimmers, any advantage to these? The one I see on sale right now is a Troy-Bilt....$249 Also, I noticed that Stihl has some decent priced trimmers now. Wondering about these and if they are a cheaper line to boost sales just like a lot of other companies have starred doing.