At 16:55 13 October 2013, Dave Nadler wrote:

I completely agree with Dave's comments; on the PIK20E ( and
maybe D) the L position (16deg) degrades the roll control so much that I
never use it; landing sequence on downwind is gear down,
flaps to +12, trim for approach speed required.
JMF

On Sunday, October 13, 2013 12:27:30 PM UTC-4,
wrote:
Thank you Bob for the detailed post. I am flying a Ventus C with
airbrake and flap combination.

Dan G

The answer to your original question varies immensely
depending on type of glider.

For your glider, first consult the manual...
Then, it depends on the type of wingtips fitted.
With the original tips you may find roll control
'uncomfortable' in landing configuration and
rough conditions, in which case don't use 'L'.
With winglets fitted (or short tips) this is
less of a problem in your glider...

Hope that helps !
Best Regards, Dave "YO electric"