Just got my first ride with the Suburban Machinery bars today, and the ride position is perfect for me. I am 6'2" and the stock setup was a bit tight, so these were ideal, racing or not. (which for me... NOT)
I wouldn't know what the racing benefit would be with these, but first I don't think that racing a 919 would get you too far, but second I do notice more immediate lean into my cornering, it is easier to bank the bike hard now and really take some corners more aggressively, with more speed.
Hope that might help.