On Thursday, May 8, 2014 1:20:33 AM UTC+12, Vaughn wrote:
The comparison isn't quite as simple as just looking at L/D. Turn
radius also has a lot to do with your chances of making it back to the
field, and turn radius is proportional to the SQUARE of airspeed.

Compare your example (40 knot stall) with a (horrors) 2-33. The highest
stall listed for a 2-33 is around 30 knots. If you do the math, you
will find that your DG1000 has nearly double the turn radius of the
slower glider.

I've done the math :-) With a 30 knot stall instead of 40, you'll want 41 knots for that 45º banked turn instead of 55 knots. And, yes, the radius will be about 56% as large, or about 65m instead of 115.

Whether that 100m difference laterally after the turn makes a difference is highly airfield dependent. On a wide field you can land straight in in either case. Somewhere else, it might put you on the wrong side of a row of trees.

In a typical place, I'd much rather be twice as far off the center line with twice the L/D :-)