My Steam version of CW loads fast. I can't see any differences to the BFC or Matrix versions.
Speaking of it, there are 3 versions, not 2:
- battlefront's (which has activation count DRM and gives you the other 2)
- Steam build (steam DRM)
- Matrix build (serial number based DRM)
The Matrix one is attractive from a DRM and management standpoint, but only the battlefront version is available for Mac.