I must confess, I’ve grown disenchanted with the so-called “slow cinema” movement as languid but emotionally arresting dramas like The Death of Mr. Lazarescu, Police, Adjective, and 4 Months, 3 Weeks & 2 Days have given way to dull pseudo-profundities like Aurora and Once Upon a Time in Anatolia. When I learned that Patrick Wang’s debut feature, In the Family, ran a whopping 168 minutes, I braced myself for another long haul, but it’s one of the best, most involving dramas I’ve seen this year. It opens tonight at Music Box.