The click is an on going issue, some say the Clark works, other say not. It's all pretty simple really. I have had all variations of the BP SD (and there have been a few) from the early 1,1/2" long clicks to the most recent.
Firstly the inner bezel teeth are not as gen, they slope backwards at an angle. Secondly, the click post hole has always been too big for the click wire diameter. I know other people have reported that this is not an issue, however I feel it is.
surely the click wire has to fit snuggly in the click post hole, it goes without saying that if there is any play in this fit it will facilitate backlash. I personally drill the post hole to 1.2mm dia and make a click from the same diameter st/st spring wire. It's not as easy as it sounds, but it does work very well when executed properly.
On a final note, A gen SD click should be and is stiffer than the sub click