I'm a homeowner looking for a new string trimmer for non-commercial use. I'm considering the Echo 2100, Stihl 55, or the John Deere XT105. All these units are basically the same price. Ergonomically, I like the XT105 the best of the three, but am concerned that the engine may be too small (19.8cc). Use will be about 20 minutes per week. 98% of the time with the trimmer head, 2% with a brush blade. Any suggestions or words of wisdom? Thanks!