I purchased a grillo 107 earlier this year and really like it. I was looking at settling on the bcs 732, but didnt like that it didnt have a third working gear. And i didnt really want to spend the money on the 853. Then i found grillos and that was the end of that. You get alot more machine for less money.
Keep in mind on the engines, the grillo has a gx340 and the 853 is a gx390. They used to be 340cc and 390cc displacement but at some point honda made them both 390cc. According to hondas website, Listed torque is the same on both engines and horsepower is within 1 hp of each other. So, engine wise i cant see the 853 doing anything the grillo wont do, basically the same engine.
Sagebrush, do you have any pictures of your cultivator setup? Id be interested in seeing it.