My Zafira (1.6) likes to drink oil and lots of it. The Flex 7 seating is very clever and you do get a fair amount of room in the back with all seats down. I would not like to ride for too long in the Zafira's last row of seats, they do not look that comfy to me!
I'm still waiting on delivery on my C-Max, so I can't offer a direct comparison!
No longer waiting for my (Company Supplied/leased) 2011 C-Max 1.6TDCi, Titanium, Manual, in Midnight Sky, with the city Pack