I am looking for anyone with any experience with either the 600 or 700 series from Grass Hopper. I will be mowing 5.25 acres all together on 6 different properties we own and am curious if the 600 series would hold up to this amount. Does anyone have any experience with any 600's and know of any weak points. Are there anything to look for or options I am going to have to order on any of these units. I want to order it right the first time and not forget anything. The yards have a few trees but mostly buildings and sidewalks to mow around. I am looking at either a 52" or 61" deck depending on which series I go with. Any advice from any others who own one of these machines either good or bad will be helpful. Thanks.