Always used to like brush hogs ( rotory mowers ) untill I owned my first flail, was an old township Alamo SHD88, got traded in on 'accident'. Gave under 1k for it, mowed probably close to 450 acres, replaced the blades once, also replaced the PTO shaft/slip clutch and bought a new kevlar belt to have on hand. Slip clutch burned up because the ol Oliver 1650 would simply overdrive it in heavy grass. Sold it for 1300 after six years of use ( ground no longer needed mowed). The cut from a flail looks better if you go slower, but I can cut more with a 7ft rotary than I could with the flail. HOWEVER, the Oliver weighs in around 8K, and a 7ft bush hog on the back makes the front VERY light, did not even know the flail mower was back there.
Flails are NOT wimpy, hitting things breaks knives, but thats it, the light sub-compacts could drag a larger flail than brush hog because the weight is closer to the tractor.
DuaneW.