I don't know if you already did it on some branch or tried this and reverted because of some unwanted side effect, however I am now binding MouseDown instead of Click and, at least on my configuration (.NET Framework 4.0 on Win7 x64), the expansion/contraction is much more responsive to rapid clicks, especially when animation is disabled.
It seems strange, why the expansion\contraction becomes MUCH MORE responsive. I didn't notice the same effect on my machine. Anyway I applied it. Thanks for the feedback, Giacomo!
Excellent component.
I don't know if you already did it on some branch or tried this and reverted because of some unwanted side effect, however I am now binding MouseDown instead of Click and, at least on my configuration (.NET Framework 4.0 on Win7 x64), the expansion/contraction is much more responsive to rapid clicks, especially when animation is disabled.