Deriving from Sprite as oppose to leaving it as MovieClip?

programming flash
1

I needed to group some simple geometries into a symbol in order to use it for hitTesting;
And I think making them to derive from Sprite class is be better in performance than leaving them as from MovieClips?

But then I have no need for setting them “export to ActionScript”.

So which way would be better performance-wise?
exporting to AS and derive from Sprite, or just leave them as MCs ?

Thanks!