I have been using the Canon XF100 (and big brother XF300) with Vegas in versions 12 and 13 with no problem. The Canon MXF files are huge and you really need a fast disk drive. These cameras produce beautiful video - although low light is a little challenging. Here is a tip, turn off all gain on the camera and you will have better video.
Great cameras. Use the Canon XF utility to download your video. No problem editing. If you use more than 6dB gain, you should get the Neat Video plugin. The dynamic range on the XF100 is extraordinary for a 1/3" sensor, Canon seems to have favored range over noise.