I've installed fireslate counters in my kitchen and am currently renovating another period style kitchen in which we are using fireslate as counter surface.
I would recommend the product as a low-cost alternative to slate or granite.
We've had ours now for nearly two years and have no real complaints. I would, however, stay away from beveled edges as it is very tedious and time consuming. A simple file followed by a light sand on the edges provides an attractive profile on the 1 1/8 inch variety. Feel free to email with any questions.