I decided to really test the abilities of both my long lens shooting technique and the in body shake reduction of my K10D. The following images were shot closer to the end of the day. It was very windy (20+ mph/30+ kph winds) and heavily overcast.
Taken with the K10D + FA* 300/2.8 + Tamron 1.4x MC4 AF TC = 420mm. I use Wimberley lens plates attached to an Arca Swiss Z1 monoball on a Giottos MT9360 tripod. Even though SR is on and not recommended for tripod work, your technique is just as important. I normally do not have the head locked in place - it swivels easily and I rely quite a bit on my technique. The tripod and the support system is simply to allow me to focus (no pun) on the work at hand. I am barely 6 feet away from the subjects, which is the minimum focusing distance (MFD) so the Depth of Field (DOF) is very shallow at F/5.6 and F/6.3.
Little or no cropping in these images. Only default conversion from RAW in ACR, no additional sharpening, minor Levels adjustment for the background to deepen it's hues in the second image. Taken ISO 640:
For reference, here is another image, taken at 1/100 sec.
Here are the links to the larger images:
From my perspective, SR certainly seems to work like a champ - more images are available for viewing on my website!