I think that is where the "best for the business" disclaimer comes in. You need to make the decision based not only on your own development efficiency but those

I think that is where the "best for the business" disclaimer comes in. You need to make the decision based not only on your own development efficiency but those you are impacting too. A recent example is at my current client, quite a large company with a lot of "legacy" investment. I can't work without using git as part of my workflow any more, but I need not mandate it for this new project. Instead we stick with svn, use git-svn to give us the features we need, and bananajour for sharing code easily amongst ourselves. We've in a sense sandboxed ourselves so our preferences don't impact the infrastructure team. As tends to happen, they eventually start to wonder what all the fuss is and want a demo of why it's cool. Now others are using git-svn too, the barrier to overcome throughout the rest of the business is rapidly decreasing. I realise it's an easy example, but with a little creativity there is often a similar solution to most problems regarding platform/framework/etc. Not always, but often.