I had an interesting call the other day with an Electrical designer that received an Architectural file from the firm they were working with. The arch file was over 275MB and they had trouble linking the file into their MEP file. They tried opening the file to see if they could even open it...but they got the system memory errors and couldn't open the file. They finally were able to open the file on someone's pc without memory warnings, but when they attempted to save it though, no go. So I had them do a Purge Unused and then try to save it...which worked. When we checked the new file size, it went down to ~45MB!! This file of course could then be linked into the MEP file without trouble.
So what's the point of this you may ask? When you are sending files out to your consultants, do them a favor (not to mention yourself) and do a little cleanup! Even if you don't want to purge your working file, detach a copy (if it's a central file) and purge that copy. It will save time copying the file to the FTP site or whatever you are using to share your files and potentially save your consultants some headaches! Or, the call from them saying they can't use your file!