Rotation impact in performance

Dear All,

I already posted this in the Game forum but I think it is more appropriate to do it here (sorry for double post)

This is a simple question. I am learning AS3 and I started by trying to do a tile game. In the process, I wondered if it is faster to tell flash to rotate a tile (movieClip, image) to be reused or add a rotated image of the title. I know if I add more tiles memory will be affected but I do not know how performance will be affected when the image rotates by script.

I am loading images from the library using addChild and I have the order of the images in a XML file. Images are small (5-10K)

What approach is better?

Thanks in advance