Posted for "Joseph Neustein,MD" <jn@elp.rr.com>:

 Colyn:
 
 I agree 100% with your assessment except I do not see how an instrument
 being TSOed helps. As you noted there are TSOed instruments you would not
 want to use.   AHRS may be an issue regardless of wheter or not is TSOed and
 used in Certified aircraft. I concur that the vagaries of our unique
 homebuilts may introduce variables that will make an instrument that works
 just fine  as TSOed and approved for installation in a certified Cessna 182,
 not function in a Lancair. Accordingly the TSO designation that a component
 was manufactured to certain standards should not have any legal or
 prognostic standing in a homebuilt as there is no approval process I know of
 for the installation of a TSOed instrument in a  homebuilt since they are
 obviously by nature all a bit different. So we are all left to "experiment"
 with what we believe are the best solutions using reliable companies, tested
 technology ( means different things to different people), and redundancy and
 not rely on a TSO designation as a cart blanc to install in an experimental.
 
 Thank you for your input and hope these discussions help all us make safe
 and intelligent decisions.
 
 Joe
 

"""
  Joe,
      I think the issue is that there is a statistical interaction
  among a number of variables totally out of your control.
  Testing tries to capture a larger portion of the statistical
  population so that you aren't dead because a few of
  those independent variables aligned one day in a way
  that will result in malfunction.
"""