Hi,
I was also curious to the counterweighted putters to cure my handsy putting stroke.
Was playing with a 34" rife mallet putter, headweight of 355gr.
Switched to a 410gr mallet head from rife (which I had on a bellyputter). Then counterweighted the but end with 160gr to get the SW back to E8, with the weight moved about 6" down the shaft to get the ballance point a bit lower to the head.
Just love the result. Because of all the added weight my hands and arms are now working together with my upperbody to hold everything together, while the actual stroke is made by the shoulders.
Tested before and after on the Puttlab, stroke really improved. Opening and closing of the face was about 8dgr +/- now 3dgr. Nice acceleration in the DSW. Much better distance control.