I'm told these are incredibly lightweight core aerators, as easy to use as the general push dethatcher/power rake. Is it as good as the Bluebird-styled walk behind aerator? I'm searching for a ride-on mower capable one (as in other thread) but keeping my options open in case I can't get what I need for my specific situation. Would appreciate your views on this machine. Are they expensive- and are they worth it compared to other brands. LIGHTWEIGHT is #1 for the amount we need to plug. Yes- maneuverability and tree roots are a factor here- bluebird was heavy as heck to turn but cored through the roots beautifully. Thanks again.