There was an article in Popular Mechanics I found on the web that
claims that the GlobalFlyer has

"a lift-to-drag ratio of 37-to-1--topping even the Voyager's 27-to-1"

(http://www.popularmechanics.com/scie...tml?page=3&c=y).
There was another interesting piece of information on the GlobalFlyer
website in an article
(http://www.globalflyer.com/ScienceAv...ilotsView2.jsp)
by Jon Krakow, the GlobalFlyer's chief engineer:

"One of the characteristics of the aircraft is that it glides well. It
glides so well that with the gear up and at light weights with the
engine at idle, it cannot descend. Switching to ground idle helps
reduce the idle thrust, but to descend at a normal 3-degree glide
angle, the gear must be extended and the drag chutes deployed."

Scaled Composite's website (Burt Rutan's shop - the designer/builder of
the GlobalFlyer, the Voyager and the SpacShipOne) can be found he

http://www.scaled.com

Looks like on a final glide the GlobalFlyer would beat more familiar
gliders such as a Grob 103 or an ASK 21... And you got a beefy
self-launcher in case you blow it...

Markus