I don't think anyone here has, but if you search THT, you will find a few.
For those who use quality, fresh rec 90, there seems to be few issues.
If you are one to do maintenance only when problems arise and only think about fuel when it runs out, you might want to pass on nizpro. However, if you are the above person and the idea of parting out your existing engines for parts and having an excuse to buy new is what you are really after, go for it!