This is what I know, but I could be considered biased
. The Gravely unit mentioned is a Parker with different paint. http://www.parkersweeper.com/parker-...spx?sort_by=36
The Parker is a knock off of our old KD series but it's only push and it's only briggs powered. The bag has a long zipper that's prone to getting stuck with debris. The bag has no downward venting bag so in dry conditions you'll be having a lot of dust in your face. I know the troubles of the bag as their's is a knock off of our old style bags. The fan is an older style that has no shredding blades so the debris isn't reduced as much as it could be. Performance wise it's not a bad unit but for the money (assuming you're paying list or close to it) there are better units out there.