in real world applications, and having used most every bp blower out there (maryuama, jonserd....) the 550 is really close to the older 420. Its great for your basic light grass and leaves on pavement, but really lacks in comparison to the 600 on and heavy type of debris. I have a 600 magnum, and absolutely love it. About to buy another 1. Like others have said, it may seem weak at first due to the engine tone, but trust me, it will do just as much as you 770 or 8500 out in the feild. I have used them side by side.