It's a great documentary and quite honest and poignant at times - not what I expected.
Yes, they were making history, but the guy whose daughter's picture appears in Gordon's locker sounds like he went through hell - also, the only woman on the team unsurprisingly had some issues with her young male colleagues.
Also, I was surprised (maybe I shouldn't have been) about how unsentimental Gabe sounds about Half-Life - by his own words he's more interested in what comes next rather than dwelling on what they've done - perhaps that's one of the reasons that Half-Life 3 has never materialised - he's simply not as attached to it as the fans are.