I got the black ones, as not that I take my husband's advice much, but he said the others look like slippers and said he would laugh at me.
I also think black inserts are more practical, especially with the amount of puddles I walk through.
The only downfall to the mammoths in my opinion is when I originally got them it wasn't cold enough to wear them and my feet were roasting.
They are just sooooo comfy - when you put your bare feet inside for the first time when you get them you just say wow.
This is now my 4th pair of crocs and I wear nothing else on my feet.