I have read nothing but favorable reviews of this unit, and of the company. I need something to re-edge beds, to install new islands, to install a variety of different edge materials, and if it cuts a bit of sod and edges a drive...great! Most of my accounts are on subsoil, or natural concrete like clay. I want to know what I can expect from this unit. How will it perform a variety of tasks in clay? I know the edger will do 70 foot in a minute in soil, but what can I expect in adverse conditions? Will I have to cut at an inch depth, and keep making passes to get to max depth? A sales rep told me you may have to go down incrementally? This might be mighty time consumeing. I am considering all the blades, do you find they are all benificial, that they all perform well? I just don't want to flop down $1700 and be dissapointed. I know their are other units out there, but most are much more money, and most seem to want to throw the cleared material into the bedding area which may not be desireable. Any and all thoughts are appreciated.