I have very limited experience with FreeBSD but when I tried LiteSpeed Linux version with FreeBSD 6.0's Linux compat layer, everything works. However, there is an abnormal amount of timeout sessions to clients via logging as compared to my linux box. This is a for a load balanced 50/50 proxy with litespeed.
I'm still trying to get the litespeed freebsd to work with 6.0. When i tried it last week with a few symlinks, I was getting segmentation faults. Perhaps I did the wrong sym links. Will try again.
In my opinion, stick with freebsd package. I wouldn't trust a 24/7 operation on a compatibility layer.