Some love them, others hate them.
I think they are a great invention if used for what they are designed for, which means no huge site clearance jobs with a crew. The patented chopping action really saves engine hp.
I've heard several times that they are slow, which I can't confirm as long as you compare them in their hp-class. They are exactly fast enough for a one man show without a mini.
The chamber style with no anvil, no huge flywheel and little momentum in the box is imho superior to other designs.
What I don't like on the newer big ones is the massive amount of electronics which won't give you any advantage in the actual process of chipping.
Steer definitely away from push units, always pick a self propelled one, otherwise you will look like a clown on wet ground/ramps/inclines.
Preferable a tracked unit, they're so light, they won't do lawn damage and can be used to drag stuff around. Light trailers or moderate sized stems work fine, you may even pull over a small tree.
And pick at least 18hp+. They have a 20" hydraulic feed, good for forks.
Go for a used, older one, best without a clutch that will fail someday. They are cheap, reliable and so stupid simple built, it hurts. New and bigger ones have insane price tags.
Just one thing: sharpening the blades is easy and they really last a looooong time, probably the stated 200hrs, but changing 20 or more of them may take 2-3 hours.
To answer your question: for a small gardener with some trees from time to time you will have a perfect match, but go used, tracked and 18hp+.
For a serious tree bizz, they are like every 20 hp gasser too small and maybe just a backup machine for tight backyards.
Good luck.
