If it is a matter of life and death, as many urgent things in RC are, I wouldn't count on those dates.

From my experience, FedEx has missed the most deliver dates out of the three - USPS, UPS, and FedEx. Second would be UPS. I have sworn I will never use UPS if I have other options. USPS has been the best.

But, just like anything, it probably depends on where you are.