Dunno man, weve got infinate as a tester, you can export out as OBJ and textures so its not too bad, not great but it can be done, ive heard quite a few problems with Xtreme though (over on GCTalk think the threads called Xtreeme Nightmare)
If it was my money though I would go for Extreeme as youve got the intergration. Think that thats the only difference.
"No pressure, no diamonds" Thomas Carlyle