UFS & serialization

[Ivan Voras]

I'm not an Oracle user but I've come across an interesting article about 
Oracle's interaction with Solaris UFS:

http://www.c0t0d0s0.org/archives/7146-Direct.html

(as well as some nice DTrace examples).

Could someone comment about how FreeBSD UFS fares compared to Solaris? 
AFAIK there is one-writer-multiple-readers semantics, and O_DIRECT in 
open(2) but it doesn't modify locking behaviour?