I understand the introduction of a save v. the stunning effect of weighted weapons. Although 3rd edition is full of no-save conditions which are arguably bad game design (vorpal, anyone?), I don't have a problem with this idea.

What I do disagree with is combining the change to a save with a drastic drop in the activation of the effect. My 5% weighted dropped to 3% with DC 33, AND if I use it off hand, it gets less activation rolls than it used to.

The effect: I toured the vale using a weighted off-hand weapon and never saw a stunned mob out of 150+ engaged. That is TOO low. It will mean that there is no reason to use them at all except when activating stunning [blow,fist].

Suggestion: combine the change to a save with a small increase in proc rate. I suggest +2% over the original proc rate, so 1% weighted becomes 3%, 5% becomes 7%, etc.