You're confusing a Death Grip with Locking the Wrists.
Referring back to Rastoff's and my earlier replies, did everyone who shot your CM9 and/or Nano experience the same problems? I've helped Nano owners, who thought they'd bought a junk pistol get better results, by adjusting their technique.The Nano (7.5ft=lbs) and CM9 (8.3ft-lbs) both have harsher recoil than the Shield (7.0ft-lbs) and it can be readily felt. This MAY be why the Shield works so much better for you.
Could it simply have been your bad luck to get 2 lemons? Perhaps, but... Just because they jammed for you, it does not prove that they were bad pistols. It simply means they were the wrong pistols for you.
My PF-9 has 8.9ft-lbs of recoil, which is why so many people initially have so much recoil control (LW) issues with it, until they modify their technique. While I get 0 malfunctions with it, many who try it can't get through an entire mag until they modify their technique.
This is exactly why someone should not buy a pistol solely by how good they feel in the hand at the gun counter. People need to rent/borrow/shoot the type of pistol they're considering, before putting their money on the counter. You don't need to know ft-lbs of force to be able to feel how it shoots in your hands.
The PF-9 was my Flawless EDC until I found the Shield.
While I could manage the PF-9's recoil, it's a chore for me to shoot more than 30 rounds with it at a time. Same goes for the Nano, XD-S, PM9 and CM9.
I figure why should I NEED to 'deal' with the PF-9's recoil, when the Shield is so much nicer to shoot (I can shoot the Shield all day)?
The thing is, LW is not a myth... Especially when it comes to Small, Lightweight Subcompacts. There are numbers to back up the real world recoil control issues. And... It doesn't matter to how much of a Death Grip one puts on the pistol.