My experience of SQL upgrades is that they tend to be largely dictated by neccessity, either of the ‘the Security team is getting really twitchy about these old servers’ or ‘crap, it’s license renewal time and the vendor doesn’t support x’ variety. I’ve never performed one that wasn’t under some sort of pressure. How do we get here?
Click through for the downsides of really slow adoption. The biggest problem is that you’re trading current convenience for future pain when slow-playing adoption, as Alex mentions.