I have been very hesitant about voicing an opinion on this subject, but
have decided to do so anyway. The last time a gave an opinion about the
suitability of auto engine conversions, I was informed that a 488 cid high
compression V10 optimized (camed) for aircraft use would not develop
adequate horsepower for our airplanes,( but I digress).
  Ever since learning about the Sierra system two years ago at Oshkosh I
have convinced myself that I could not possibly build this airplane and not
include these avionics. The only problem is the price. A panel including a
two screen Sierra system would be more expensive than the combined  total
of the rest of the airplane. What is one to do?
  Then came along BMA EFIS/One. I was intrigued with the advertising, only
to have my hopes tempered by the somewhat negative press on this list by
several well respected individuals.
  Being the type of hardheaded person that likes to form my own opinions, I
went to Oshkosh this year in search of answers.
  I finally stumbled across the BMA tent and half expected to be
disappointed by what I would see. I was NOT. On the contrary, I was very
impressed. After grilling Greg Richter on two separate occasions I came
away with a very satisfying feeling of knowing that synthetic vision for my
plane is no longer a pipe dream, but a reality. While I believe the
argument that the hardware cost on the SFS is as high as the BMA retail
cost, this does not change the fact the SFS is simply out of what my and
most other experimental builders could possibly afford. According to my
calculations, I can build a panel comprising of a two screen EFIS/Ones, a
backup EFIS/lite, a two axis autopilot, Garmin 540, transponder,
weather/lightning/trafic,interface, AOA , for about 35K. Still high, but
within by reach.
  While I agree with the argument that the BMA will not be as reliable as a
SFS, to be sure a redundant EFIS/One/EFIS/lite system is more reliable than
the steam gages that 99% of GA aircraft are flying behind now, and if you
want to increase your reliability even more, you can buy two complete
EFIS/Ones and an EFIS/Lite for about two thirds the price of a single
screen SFS.
  I don't buy the argument the system won't work because it lacks the
incredibly expensive hardware at all.
  I am not trying to convince any one of my opinion hear. I am just
suggesting that you form your own opinion, on your own, don't take my word
for anything. If you can afford the cost of a SFS, but all means, buy one.
It is an incredible system, but if your like me, and can't afford to spend
half a million on your airplane, you owe it yourself to add least check out
the Blue Mountain.

Mark Lally
ES 20b turbo
BMA EFIS