There seem to be known pains when using AWS, for example Reserved Instances:
" you can retire your “Ministry of RI Optimizations”. Stop playing RI tetris, seriously — the sadomasochism is entirely optional. " - from https://hackernoon.com/why-googles-answer-to-aws-reseved-instances-is-a-big-deal-4b9b36d8e631
Even AWS recognized this to be painful, which is why they announced today about flexible instance size with regional RIs https://aws.amazon.com/about-aws/whats-new/2017/03/amazon-ec2-reserved-instances-now-offer-instance-size-flexibility-helping-you-reduce-your-ec2-bill/It is as-if everyone knows that this is a painful thing, and just waits for AWS to do something about it.
What are other known pains when using AWS, or other public clouds?