To answer your questions:
quality of materials? Both are very good
ease of building? Not much difference here The CA kits are pre sheeted foam surfaces. Very quick build. (I personally own 2 of the 27% CA planes)
finished weight? About equal. This depends more on your building the kits.
3D capability? Many would give the Edge a plus in this category. The CA will still hold it's own.
precision aerobatics? This is where the Extra will shine. The Edge is not known to fly and score sequences well. One big name competitor stated "If you're flying an Edge you will need more than practice". The problem is in spin and snap entries. The Edge doesn't do this well and the straight leading edge keeps the wing from stalling.
appearance? I don't mind the looks of the Edge as is really is a modified Laser with better moments. The Extra is a classic in it's own time. This is a matter more of personal preference.

I would personally choose the Extra (as noted above) for the best of both worlds, however if 3D is really what you are more interested in then the Edge. Every aircraft is a compromise in one way or another.

Hope this helps,

EXCAP232