One more suggestion, as a former revolver shooter you may not be gripping the gun as high as you can, or as tightly as you should. This allows the pistol to recoil excessily in your hands ("roll"?) and does not allow the slide to achive sufficient velocity to achieve full travel to properly pick up the next round from the magazine, and results in a failure to feed. This is sometimes refered to as "limp wristing". A seconday effect is that it takes longer for the pistol to recover from the recoil and get the sights back on target.

This is not unique to the SD, all autoloaders operate in a similar manner.