Provisional
I remember when PING came out with the first CRAZ-E mallet putter.... I putted lights-out with it, and honestly don't know why I ever got rid of it. (It was the blue-colored mallet putter).
Then a few years later came across the PING iWi mallet putter with the weights. Chopped the shaft down to 31" (to get my eyes more over the ball in my setup) and added the max weights to the heel and toe... threw on a mid-sized putter grip to help take my wrists out of the stroke and have never looked back.
Probably the best putter they ever designed imo.