We only use ours for lawn aerovation and brush cuts. They are great machines and have many attachments but are quite expensive if you can't use them on a regular basis. As far as mowing another company near us has one and he said its a PITA to mow with unless its a large wide open property.
They are a great machines they allow me to mow a lot of times when my zero turn can't handle the conditions. i.e. wet, swampy area's, difficult hills.
They are also great in open area's.
I also have a stump grinder and slip scoop and a tough cut deck, that I use as well.
However others are correct, they are pricey and are not efficient on medium to small yards that require a lot of turning.
It is really a personal choice and what fits for your company.