I don't know if I would draw that conclusion. As HIRISC said, 5.1 seconds was just a 'feeling-out' run by this one team. But there are a lot of non-launch numbers coming out now, from other publications like Car and Driver and others, both with the X6///M and X5///M. C&D got 4.3 seconds on a pre-production X6///M that did not have launch control. If you then translate that to BMW's official stats that put both the X6///M and X5///M as "equals" (with both listed at 4.5 seconds by BMW) I would think the X5///M should get within 0.1-0.2 seconds of whatever numbers are obtained for its' X6 cousin. So based on what we're seeing in print thus far, if you just gun it from a traffic light without LC or even torque-braking, you should still be below 5 seconds on a 0-to-60 sprint.