Update
Got the Apex. Install was pretty uneventful. What a difference! I don't own a scale so I can't provide actual numbers but, the weight is significantly reduced while still being smooth as glass. I've put a little over 100 rounds of mixed ammo through it without a hiccup. (110g +P through a few different 158g loads) Still want to shoot it some more before putting her into service but, the Apex has taken my 642 from a gun I never used because I hated the trigger so much to one I look forward to carrying.
Now I just have to decide on a pocket holster......