Auto-save is always a pain when you're dealing with the 100+ megabyte files common in publishing. The only thing that can solve that is a fast, multi-processor computer and a really fast hard drive. Or even better, an XServe RAID attached with fiber. 400 MB/sec write speeds shouldn't slow you down much even for huge files.
You know what is really slowing things down (and likely causing the crashes)? They are using up so much system resources to watch everyone to make sure they areworking fast enough that they are slowing everyone down.