I hope the Leica R to SL adapter will be better behaved than the R to M adapter. Please see:
http://www.l-camera-forum.com/topic/253927-apo-extender-2x-question/?p=2942981
http://www.l-camera-forum.com/topic/253927-apo-extender-2x-question/?p=2944668
Hint: Leica, please take note. Otherwise, everyone will use a Novoflex or the stacked R-M-SL adapters. Also, we need the full aperture focus / close-down feature. To sell a High-priced Leica-branded adapter, Leica has to include the High-level features!
Guy