I upgraded my iPhone 6 the other day, and have had absolutely no problems. And, I've been very happy with the changes I've seen so far.
At one time, I was developing software that was used on over a 100,000 computers in businesses all over the country. Every time we released an update, a few computers would fail for one reason or another. It had nothing to do with the quality of the software. It was simply because in a group of computers that large, there were always at least a few that were right on the edge of failing for hardware-related reasons. Rebooting the computers would be enough to cause them to fail, regardless of the version of software, but since they never rebooted their computers except for when they were installing a new version of software, the two seemed to be related.
For those unfortunate few who had problems, the fact that 99.99% of the upgrades worked flawlessly never convinced them that the problem was something other than the new software. They were always certain that the software caused the problem, even when wee could prove that, for example, the power supply failed. They would claim that the new software was responsible for making the power supply fail.
Yeah... Well... That’s, like, just your opinion, man...
Q: What is “significant numbers”?
A: Each and every single expensive product which no longer functions normally despite the quality money and time expended for it by the customer.