[ardy42]

Were there any scientific utility to these payloads, or were they added in order to create some spacecraft porn? How much did the equipment for this weigh?

IIRC, a downward facing camera is useful for precisely locating the landing location, but I'm having trouble seeing a purpose for the upward facing camera besides getting cool sky-crane video.

[sandos]

There is an engineering use for it, and that is to the see all the dynamic behaviour that other sensors might not capture. This is rocket science and they do want to know how the landing went.