I can vouch for these results, it's the primary reason I'm sticking to KLM rather than flying Lufthansa via FRA/HAM/MUC or SWISS via ZRH. I've had no delay greater than 30 mins (and only once as far as I remember) in the last 3-ish years that I've gone KLM-exclusive while I was frequently delayed by more than that on LH and LX and stranded at FRA.