I bought a used Perma Green Ultra and used it for the first time today on 5 of my lawns. I love the increase in my productivity but I think this machine could have been designed better. I know I will have to get used to it but this thing does not stop very well!! The first lawn I did was my own and at the end of my first pass I am coming to the back of my lawn that has a slight downward slope and BANG!! Ran right into a raised retaining wall. I let off the throtle at least 10 ft before I hit this thing and was standing on the brake. The problem was the wheel just locked up and skidded right down the slope. Now this is a very slight slope. It only drops about 1 foot over 10 ft span. Any PG owners have any insight on improving the stopping ability on hills?