In fact, the second half is somewhat a let down after the first. The play has few scenes--by which I mean, where characters in a given time act on each other through talking or other things--and instead has a lot of narration and some longish remembering "arias." That said, the next day after seeing both parts in the same day, I felt the 7 hours was an experience more like reading a novel than seeing a play. I had moved through time with the main character and found myself thinking of his life often.
BTW, the comparisons with "Angels" need to be further described. Yes, "The Inheritance" is a 7 hour play about a group of friends, mostly responding to the effects of AIDs. The group is later in calendar time from "Angels." Lopez, however, is neither as clever nor dramatic as Kushner. Don't go if you're expecting the roller-coaster ride one's first viewing of "Angels" was.