My 2 cents, as far as I know 7.1 will be maintained longer than 7.2 according to the freebsd.org website. That is, security fixes will be rolled out for 7.1 a while after 7.2 reaches End Of Life. That made me decide to go with 7.1 when I had to make the switch from 7.0 a few months ago. 8.0 was not out at that time.