The older Troy Built models like the Tomahawk seem to get good reviews. Just as you describe, they are what they are and they do the job intended. All these modern MTD and such, about half plastic, and with over rated Chinese HP motors, everything I read about them makes it sound like they are suitable for mulching trimmings from ornamental bushes and flower gardens along with shredding leaves, but forget the Mesquite, fruit trees, and the Oleander that I want to remove.
I've been cruising CL and it's new competitors for nearly a month, and the best I've found is the larger MTD "10 HP" units for around $400. I talked to a guy today that had one posted not far from me, but turned out he already sold it. So I asked him, since he no longer had any reason to spin his answer, why did he sell it and what was his impression. Basically, just as I said. He had a larger 30+ acre up in New River, covered with Mesquite and other scrub, and wanted to clear a large portion. As I suspected, even the big boy was marginal. It told him my goals, and he answered (I believe honestly) that he recommended getting all the cutting done with piles, then renting for a day. He thought even that larger model would be frustration, and he's in the market for a "real chipper".
My needs are far more modest than his, and frankly after the big job I see now that cool weather is here, most of my work is maintenance mulching of Mexican Heather and trimming Mesquite overgrowth. So I may yet get one of the bigger units if a Tomahawk or PTO chipper doesn't surface in the next few months. At least I'll have it for conveniently mulching leaves and smaller branches that make up the large part, particularly if I keep on top of the pruning.
I've also been pondering what it would look like to build a PTO chipper. As expensive as they are, it still seems like a lot of work for return, particularly when I already have more projects than time.