Id go for the murano,
Import resale value will hold alot better vs then enclave. Do they see themselves switchin cars again in a few years? Do they want to get a little more for their money in the end when/ if they do trade it in?
Im not sure of the buick familys relibility, but IMO anything domestic ive purchased has been a headache in one way or another (ive had ford, chevy and olds). With nissan ive had very minor problems over the last 4 years and its worth more to me to have the peace of mind knowin that shit wont break.