I saw a guy using a nice dixon ztr with a 40" deck and it was cutting moderate st. aug and was doing a bad job. I go back later and saw that it missed spots and didn't do too well. I saw the same guys cutting annother house and the back yard looked bad after they cut moderate st. aug. Is it my imagination or do these big mowers cut bad. My snapper 21" could have done it better. I used to cut with a guy who used a gravely zt 1640 and it cut kind of good but still looked like my snapper push mower could cut it better. What's true about this?