I was troubleshooting a part that we were having problems when making a drawing of the part. I loaded the 2013 part into 2014 sp1 and saved it as 2014. The file size of the part went from 965MB to 4.3MB.  Opened and saved the drawing and the part file size increases to 20.5MB.  Go back to the part file and open a sketch or start a command to get the asterisk to show and save the part only. File size back to 4.3 MB.  In 2013 it is worse  53.9MB -> 368.6MB.   I did a file -> save as to get the smaller size in 2013 then opened the drawing moved an annotation and saved and got the increase. In 2013 saving the part file alone does not make it shrink like it does in 2014.

Why is this?  The part is a multibody sheetmetal part with several flat patterns and some non bent parts. Has anyone else seen this?  We seem to get along ok with sheetmetal weldments until it comes time to document them in a drawing.