I made a red/white/black one last winter. The directions stated to get a sweatshirt one size larger than normal because of the shrinkage due to quilting. However, mine came out HUGE....so I had to cut it down more than expected.
I love mine and hope to do another one some day soon!
And yes, I used the outside of the sweatshirt as the inside of the jacket...rather than the fleecey part. I also took off all of the ribbing and bound the whole thing in the end. I wish I would have made at least one pocket for my cell!