Is FLARM helpful?

At 12:26 24 November 2015, Ramy wrote:
... (With handful of Flarm saves in over 1000 hours with Flarm)

Interestingly, my experience is just the opposite: in 1593 hours in
the French Alps since 2007 (only 208 hours of which were without
Flarm), I have had no relevant alert from Flarm but hundreds of
false alarms. However I have experienced several dangerous or
very dangerous events (and many more daft ones) which can only
reasonably be ascribed to Flarm - or rather the false expectations
that some pilots seem to have of it.
The most stupid of these was two gliders simultaneously overtaking
me at speed from directly behind on a ridge, one each side, at
exactly my height, and with a horizontal separation of about a
wingspan. Fortunately, I had insisted that my pupil did *not* take
evasive action from the Flarm-announced threat, pointing out that
we might just turn into the path of the (imagined) single overtaker.
(I presume that the 2 overtakers thought "they know we're coming,
so they won't do anything stupid"!)
In the 2000+ hours in the Alps before Flarm I saw no such
dangerous behaviour; nor in the 208 hours 'gap' without Flarm in
2008.
Of course, nothing can be proved. But enthusiasts for Flarm should
be aware it has its down-sides.