Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I ran into that too. My library is 400 GB. I could either restore locally and let it upload everything, or just open fresh and let it download everything. I tried it partially both ways and wound up going with the local restore. The download seemed only to get all the thumbnails and download full files when items were viewed.

Very poor implementation. Now I've already blown through my monthly Comcast data cap for October.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.