I went into a gravely dealer today to get more information and talk about ordering a 460 and I cant decide which of these two engines I should get. I did do some searches but I know these are two very popular engines and I figured that it would benefit a lot of people if they could share their opinions.. It is a 60" cut and I bag about 50% of the time and then just side discharge the rest of the time on my properties. I do have some hills but nothing crazy to go up. I currently run a 52" Lazer Z HP with a 23hp kawi and that seems to do fine. I would prefer to get the 27 hp (formerly 31hp) 850, but I want to make sure that it will have enough power for what I do with it. I am fairly heavy too, about 235 pounds So basically will the smaller engine have enough power? How do these two engines compare GPH and powerwise?