A few of us low time club renters are considering buying audio variometers
to help keep our eyes outside the cockpit and our planes in lift.

One unit we're looking at is from Blue Sky Avionics, the M12 Cricket
http://www.blueskyavionics.com/M12_Cricket_HG.htm

There's also a fancier M19.

Does anyone have experience with these? Do they make sense to use?
Thanks.
Wad.