Hey all.
I thought I'd weigh in on this one. Just so you understand my perspective... I had my doubts about the new sheath configuration myself. I have occasion to need rapid access to my blades. Both in training and in the real world. I have found that in my particular case, the "new" design does not pose a problem with retention, clearing, or resheathing the blade on the BA3 or the GM. Below, I will attempt to outline my clearing and resheathing procedure.
1. Carry: Right side at the 3.5-4 o'clock position.
2. Clearing/Presenting: Grasp handle with thumb and middle, ring and little fingers wrapped around. Forefinger lands under the snap tab on the forward side. Simultaneously push index finger toward the rear, releasing snap while cocking arm upward and swinging forward like a pendulum as index finger wraps around handle.
3. Resheathing: Hook the 550 cord with middle finger (knife hand) and pull taught. This positions the tip of the blade at the lip of the kydex liner. Drop knife back into position in sheath and loop 550 cord once around the handle and fasten snap.
While this may sound complex, it works and works with only the knife hand doing any work. Granted, it does require some manual dexterity and subsequent practice but, try it slow a few times, make adjustments for your particular body type and movement style and I think it will work rather well.