The V3/V7 price difference is interesting. It must be mainly justified by
marketing rather than the different electronics?

Hi,

There is a big hardware difference between the V7 and V3. The V7 has pitot
an static inputs and can therefore display push/pull (speed-up/slow-down)
commands. The V3 does not have pitot or static inputs. It can tell you how
fast to fly, but it doesn't know how fast you are flying, so it can't tell
you to speed-up/slow-down. The V3 is a great new idea. It is a Total
Energy vario with audio, with the ability to display the recommended
speed-to-fly based on your glider's polar and the current MacCready setting
and the current lift/sink. It is a lot like having a smart MacCready ring
on a mechanical vario. You can see details he
http://www.cumulus-soaring.com/lxnav.htm#LXNAV-V3

Best Regards,

Paul Remde
Cumulus Soaring, Inc.