I really wanted the new top hat, because, well, it is a top hat.
I figured the UMD bonus must stack, because there is a +1 UMD item on Korthos. And resistable dance as a clicky is … resistable … easily … meaning … not so useful.*
*See I am being nice there are many other words I could have used other than “not so useful” 🙂
But no, it does not appear to stack.
So I wonder, maybe it is only good when Epic-ized? Nope, the Epic Big Top has only a +3 enhancement bonus to UMD. There are several lower level items that have this or better, including an easily obtainable minimum-level-seven end reward.
But the dancing is upgraded and is now Irresistable. Is that the point? Three dance charges now available to non-casters? At caster level 15? Against Epic monsters and spell resistance?
I am underwhelmed.
It sure does look cool though.
[Correction] The UMD bonus DOES stack with other items including the Golden Cartouche. Thanks to Modulex for pointing this out. Even so, the epic version of the hat remains underpowered.