I have an older Jari and I like it very much. It is great for places you can not take a bush hog or where things like cans, bottles, logs or other things may become missiles from beneath a bush hog. Mine is 42 I think and it will cut a path thru high weeds very well. It is dangerous to use around dogs and other pets as they may not see it coming and quickly lose legs or paws in short order.
It is quite fast and can climb hills faster than I can after about an hour of mowing. I usually run a little above idle and the motor is never strained. It is sometimes stalled by larger stems and stocks (above 1? but given a few seconds it will cut most anything that will fit between the guards of the sickle bar.
There is some maintenance with belts and cutting bars and the weeds are left laying where they fall and not ground up like a rotary cutter. This may be the only draw back that I see. I occasionally mow the yard with it and it is not a fine finish mower. For orchards, around ponds, under fences and in hilly areas it is hard to beat.