As you've gathered, I would prefer simplicity, and the last thing you can describe FATCA as is simple. It is clearly a very complex way of dealing with it, so I don't think it's ideal.
I believe that Europe is actually going to provide a better model for this. The European Union Savings Taxation Directive is now making progress. It was blocked by Austria and Luxembourg for some time, but if you want to look at a model as to how to go forward, I think the revised savings taxation directive is a much better way to go than FATCA.