Aquathing I haven't tried the Amazon feature, but on my P9P running GOS, the Google Maps AR features do seem to bring my phone to its knees after a short time. IIRC, it continued to be slow until reboot (even after AR features were no longer in use) in at least one instance.
I assume it doesn't happen on stock P9P, since that would be strange, but I haven't done a comparison.