Here in Ga they still cut ROWs with Tractors and bush hogs and there is no skid steer mulcher in the world that could cut what they do per acre. A rotary cutter is design to cut the material, a mulcher is designed too mulch. Obviously the cut material will be left rough and the mulched material will be mulched much smaller.
In my opinion a rotary cutter is an exceelent choice for doing what you asked about as long as the rough cuttings are not an issue.. I would suggest a larger ctl ( than a 259)however. Not sure why you think you need a small CTL to landscape with?
look on Dirtmans picture thread, as he has a nice cutter on his TL150 and a bunch of pics of work with it.