I have found that there is a big nfs performance problem with Homestead 2.0 and Ubuntu 16.04.
It is slow as hell, over 20 minutes for a Laravel composer install... I have found the problem, and share it with you here:
You need to add o the Homestead.yaml file under the type: nfs
options:
linux__nfs_options: ['async','rw','no_subtree_check','all_squash']