Updating INPUT's "value" doesn't work if it has been edited by the user.
<input type="text" value="{$this.mytext?$this.mytext:'nothing changed'}">
<button
onclick="{$this.mytext='default text';alert($this.mytext);$this.refresh()}">
test change
</button>
I found the same problem in these issue:
google/incremental-dom#239