I've used this metric but intelligently - I've used tools to SEE what is covered or uncovered. Simple constructors or accessors that end up not getting coverag

I've used this metric but intelligently - I've used tools to SEE what is covered or uncovered. Simple constructors or accessors that end up not getting coverage are fine, I believe you can see that you have little risk in not writing test for them. If you're shooting for package-level tests and you have no separate tests for POJO's (in Java) - little risk there. But if you see a big section of exception handling that has not been tested -- that's a sign of a risk. Test that stuff.