Eric Greenwell wrote in message ...
It's not 150 pounds when it's flying, but with the pilot, typically a
BRS, instruments, battery, etc, it's between 350 and 400 pounds. That,
and the small wing area give a 5 to 6 pound/sg ft wing loading. It's not
a "floater".

Definitely, the wing loading is important, not the only weight of the
glider.
When we know that the Silent-2 with its 663 pounds of MTOW (298 lbs of
empty weight) and 7,0 lbs/sq ft, reaches L/D of 39:1, also the figures
given for Sparrowhawk seem to be realistic.
Is it possible to fly cross-country with an ultra-light glider ?
After flights of Leonardo Benetti-Longhini, reaching with the Silent-2
a 627 km free distance, the definitive answer was given by Dave
Stevenson jr, who pushed with the same glider the FAI DU world record
of distance on 904 km ! :-)
(http://records.fai.org/gliding/pending.asp - file ID 11488)
Yurek