All putters are a weight on the end of a stick.
But I'd say this; in recent years I've only used a modern putter once, that was a TaylorMade Spider, don't know what model. But I can tell you that it was very stable through the stroke, in that it didn't feel as though it would come back to the ball other than how I'd lined it up (and I holed more of those tricky 5 to 10 foot putts than I normally do).
The same can't be said for a true blade putter, and when I say true blade I don't include mallets or Anser styles. When I use a true blade I really have to concentrate on returning the face square to where I set it up, and ensuring that I strike the ball on the sweet spot.
So why do I continue with these old putters when a modern putter is so much more stable? Because I enjoy using them and the satisfaction I get when I have a good putting round.