I recently had an experience which underscored for me the power of AWS CloudFormation. My test lab is almost exclusively run in the cloud now. So when I need to demo things before discussing them with a customer, I build environments in AWS. One such environment was for SQL Server 2016. The original idea was to use Windows Server 2012 as the OS with SQL Server 2016 as the database platform. The customer recently decided that we should look at Windows Server 2016 as the OS instead.
I was able to adjust to the customer's request by altering two lines of code - one per EC2 instance. That's it! Just two lines of code, and I could redeploy the whole setup. The only lines that needed to be updated were the ones referencing the ImageId property. Previously, I would have built these servers in VMware workstation or Hyper-V and it would have taken a few hours. Now, it's just minutes.
Overall, it's tough to beat the speed and flexibility of leveraging cloud services and code.