I mostly agree with the previous answer.
The FA and DA will not give you exactly the same. DA is an swiss army knife to me, it's compact and can do macro. But if you need faster AF and better low light, keep the FA.
Regarding the AF of teh DA, yes, it's slower becauce it's a Macro lens. It's as designed - the lens wil sometimes go back and forth before focusing, and the AF course is quite long. You can work around this by manually pre-focusing... It would be great to have a focus limiter there, but in such a tight package, probably not possible