Q. When creating a custom image to use in Azure is it better to start with a regular OS image or one from the Azure gallery?
A. The Azure gallery contains a large number of images that have already been customized and tweaked to give the best performance and functionality in Azure. Some of these are big changes others are small and may relate to items such as time zones however all the work has been done. I therefore recommend if you are creating your own custom image to use in Azure then actually start with a gallery image, customize it to your requirements then SYSPREP it and make it a template. This ensures it already has all the Azure "tweaks" to ensure best functionality.