Review (3/5): Best for Professional use - too difficult to control when using it on yourself.
3 stars for self handling
5 stars for power
This is a very powerful tool and will remove any type of callus.
When considering this tool, realize that it is very difficult to control - press too hard and it either jumps away or possibly burn your skin, too little pressure and it still jumps away. There is a perfect touch and once found, the tool works great.
Orbital sanders can be engineered correctly to eliminate jumping and can be designed to use in any direction, but it costs money and I feel this tool is best used by a professional on a client than it is to try and use it on yourself. Having said that, some of the roller types work really well, except they lack power - but that is probably to prevent burning.
Consider lightly lubricating your feet before using this tool.