On Sep 27, 1:49*pm, John Smith wrote:
It depends on what you want it for. If you're planning to do intentional
serious cloud flying, then you should be aware that none of the devices
you've mentioned is TSOed. Legal issues aside, I wouldn't put my life in
the hands of a device of which I don't exactly know how reliably it
performs.

If however you're just looking for a safety device, then probably all of
them will let you to keep the wings level. You could also consider to
buy a used T&B (the classic form, not a turn coordinator!). These speed
up reasonably fast, are extremely reliable and deal fine with any
attitude. You'd need some training, though, to be safe with a T&B.

Don't get too enthralled with TSO'd devices. It's little more than
the FAA's "good housekeeping seal". A fair percentage of airplanes
routinely doing "hard IFR" have non-TSO'd gyro instruments installed.

A TSO simply means the manufacturer submitted paperwork showing the
device met the minimum standards for a functional device. I've had
more reliability problems with TSO'd instruments than the other
variety or about a 400 hour time-to-failure. I had so many gyro
failures over the years, I kept Sporty's black suction cup disks in
the side pocket to cover failing instruments. The only real safety
"device" is very good partial panel skills.

From what I hear, Dynon instruments are far better than those TSO'd
gyros.