Comparison of depth of field methods:
3DMax vs After Effects

Depth of field camera effect created in 3D max R4
using multi pass camera effect
12 samples 4.0 sample radius
render time: 2:00 minutes

Depth of field camera effect created in Adobe After Effects
rendered without any effects and saved as RLA file with z depth plane
z depth extracted and used as a mask for two blur adjustment layers
render time: 12 seconds + 3 seconds in AEX = 0:15 minutes

Conclusion: If you are rendering stills, the 3D max method produces
slightly better photorealistic depth of field blur.

But if you are creating an animation, the AEX method is a lot faster and
looks good enough to fool the eye. Not to mention it's a lot faster,
thus you will be able to create a movie that is 10 minutes long vs 2 minutes