Hardcore servers is the key for BF3.
Make respawn time quick, people don't want to wait too long to get into the action.
I have had some crashes yesterday, so far today it's been great.http://www.47r-squad.com/battlefield-se ... h-fix.html
This was posted by John, and I can confirm it fixed the issue for all of my 5 servers (even non NFo).
Here is the screenshot of my settings.