I don't have a troy built mini tiller, but I have a troy built weed wacker/brush cutter. I wouldn't buy it again, its sort of cumbersome to use, too heavy for long use, the drive shaft has a tendency to torque up, and the engine does not want to stay started half the time.
[Thcri: I am thinking of getting her the Mantis brand which is up there in price also.]
My SIL has a Mantis brand tiller that I have used a few times. Its an older one but it still works/runs great. I used it earlier this year to dig a hole for one of those plastic pond basins. The tiller is easy to use because it is so lightweight but has plenty of power. The Mantis even has a lifetime warranty on the tiller tines, break a tine, and they will send you a new one free.
"The Mantis Tiller/Cultivator's patented reversible "serpentine" tines really bust through tough soil. The competition's "bolo" tines just bounce off sod or hard soil. To compensate for their "bolo" tines, most other mini tiller manufacturers offer optional "digging" tines – at an additional cost of $50 or more! What's more, our tines are guaranteed for life against breakage!"
Jim