Defocus node gives too many problems.

-many times you get aliased edges
-Many times you get ugly,wrong blurred edges
-Many times you have to use FSA , this slows rendering times a lot

Why not make the blur node ableto to use the z info ?
Also it would be cool of all the nodes could use the z info. that would be relly cool.

Hmm I thought the depth blur node DID use the Z info. It is just a post effect, so any close (infocus)edges that are next to very distant edges will be unavoidably blurry. To elliminate this you need to render background and foreground elements seperately then composite them.

Supply an example .blend and see if someone cant improve your results

I don’t see any problems with…it’s all in learning how to use it. ALL Blender composites are better off with FSA. Besides, it beats the alternative of down-sampling Hollywood sized renders and you get a myriad of sample filter options V.S. some single, crummy, scalar, down-sample which many programs really suck at.