Depending on the (physical) size of your family, I cannot imagine more than 3 people in an NX. It would just feel claustrophobic.
My family is pretty tall - 12 (already 5'10') and 16 yo - and even our RX feels tight (like a Honda Accord with a cargo area) with 4 of us in it, honestly. Front is great, back is tight. I think it would be difficult to take more than an overnight or two in terms of luggage (1 bag/person).