I have one. I think they are the best convertor company on the market. I would be hard pressed to buy another from anyone else. If you gave them honest answers to their questions, it should be right on as to what they say it will. Mine is supposed to stall 6000-6200, it stalls right at 6200.
I know lots of people running Coans, but I haven't ever personally. High end converter!
I have never heard anything bad about a Coan converter either.
For what it's worth, give Gary Marshall a call at TCS converters. (they're located in Canada). Also, great converters!