"I have a more powerful 1/2 hp Mastercarver but they cost more than a genuine Foredom."
Both the Foredom TX 1/3hp model and the 1/2 hp Mastercarver use the same wattage (same horsepower ), Foredom uses a more realistic horsepower designation. Foredom runs at 15k rpm, Mastercarver run higher at 30k rpm. The Mastercarver has a reverse switch setting, the TX does not (but the TX could be modified). Foredom is a standard flex shaft, Mastercarver is not. Priced basically the same.
From what I gathered, few ever use a reverse motor direction feature, anything over 18k rpm causes premature excess wear, though it would be nice to have for occasional use. Foredom has large number of accessories/hand pieces, not including all the sanding , grinding, cutting accessories common to both. Foredom's TXH square shaft (older model) is more suited for mechanical shop use, as the square shaft is rated twice as strong as the keyed shaft on the newer TX model; trade off is the older model has far less hand pieces to chose from.
Basically a draw a to quality, power, price. Foredom ahead as to accessories.