Has anyone used the DR Tow-Behind 7.25 All-Terrain Trimmer/Mower instead of sickle mower? DR claims a 4ft offset to mow close to pond edges, banks, ditches, etc. not sure how safe that is. DR is also cautioning to go on no more than 20 degree slope. I know sickle mowers cut along the entire length of the bar & can handle small trees & brush with ease. DR only cuts with string, but is claiming large string can cut heavy brush. Cutter head is only about 20 inches, but the price difference is a lot.