I've read in a couple of places that PEX was not recommended for the drop from a shower valve to the tub spout and should not be used from the valve to the shower head. I'm not sure i understand why.

I am hoping to use PEX in my shower from the pressure balance valve to the diverter and then from the diverter to each the rain shower head, hand wand, and the body spray pressure balancing loop.

Are there any opinions one way or the other on this? Thanks for the advice and help