I wouldn't run a harness on the street regardless, it's too restrictive for turning your head, etc. These two stories you're talking about were un-helmeted heads hitting 4-pt rollbars?
And yes, the side airbags are in the stock seats, whereas the curtain ones come from the roof. No doubt everything is tradeoff, I'm just trying to find a reasonable tradeoff. I'm a pretty safe driver on the street, I think, but I can't predict what other idiots will do nearby me with infinite precision
I guess I should preface all of this with those sorts of blanket statements about how most people survived ok before the advent of X, and all modern safety features as for corner cases, it's all a percentage game, blah blah. I get all of that, hence finding a reasonable tradeoff. I just don't want to do something in the name of increased *track* safety that seems like a really stupid (and life-altering) decision due to an unpredictable street collision, in hindsight, because it made the situation far worse.