I just completed a set of three video tutorials on how I integrate Xara Xtreme Pro with Toon Boom Studio. The tutorials include basic character construction in XXP and how to get it into TBS. Then, how to separate the various pieces, rig and group them and finally, animate.
Check it out at my YouTube channel at http://www.youtube.com/user/Zebtoonz.
Both programs appear to work seamlessly with one another and Xara is quite a bit cheaper than Adobe Illustrator.
And, Xara, IMO is much easier to use!