Quote - Question: has anyone tried the smoothing brush on the jagged edges where the conversion doesn't go so well? If that's the case, there may be a way to make it look a bit better. I know it works for dynamic cloth.

Do you mean the smooth polygons setting you can apply to objects or groups...or something else?  I'll give it a try, once I know what your talkin about  ;-)

Now we need a bunch of hair fits!  ;-)

For Hair, I have fit a couple of 'em to see how they look, and I have found the following, which may get you 75% of the way there, if the hair is propped in its place for V4:

• X Scale: ~93%
• Y Scale: ~93%
• X Rotate: ~2-6% (depending on hair)
• Y Translate: -0.65
• Z Translate: -0.8

...again, these won't fit hair out of the box (from the V4 pose), but for the 3 or 4 hair I tried from different vendors, this got close, then I tweaked a little on each.  The rotate was by far the most variable of course, cause of the center point of long versus short hair.  Hope it helps! :)