I think somebody got bad info... 'Bush Hog' is one of -thee- brands. It's use has become so common that most people refer to a rotary cutter as a 'bush hog'.. similar situation with inline skates, and rollerblades.
Bush hog makes a fine expen$ive product.. and is heavy duty.. they even have a tougher line called squealer.
Most of the other ones you see like howse, land pride, and king kutter are medium to light duty... with some of the chineese import stuff being light duty. Woods I would also class as heavy duty, as well as many of the dealer name brands... like the JD, NH and kubota lines.
The heavier the duty.. the more money. Buy what you need.
As someone else pointed out... if you buy a 565$ KK 5' mower.. don't expect it to do everything and last as long as a 1100$ bush hog model.
One thing to considder is weight.. I specifically bought a medium duty KK due to the lower weight, so that I could use it on more than one of my tractors.
Soundguy