At its best, the play is an entertaining, and ultimately touching, study of these characters; and the new production -- which the Roundabout Theatre Company imported from London's Old Vic (with a new cast) -- delivers that with predictable warmth and ease. The polished authenticity is established immediately by Peter McKintosh's handsome set, which captures the upper-middle-class comfort of the Winslows' existence in the years just before World War I... As that comfort is threatened by Arthur's crusade, Roger Rees makes the toll physically palpable. Rees' Arthur seems to age before our eyes, growing wearier and more feeble, but retains the overwhelming devotion to Ronnie that transcends family pride. It's impossible not to root for this patriarch, even when his loved ones are frustrated by him...The truth, while more complicated, is no harder to predict than any of the developments in Winslow Boy; but this winsome revival will charm you nonetheless.