I can weigh in here. Based on using the 7.1-BETA and on using the following settings gleaned from the FreeBSD ZFS tuning wiki page regarding 32bit systems with memory pressure...
... and I find everything somewhat stable.
Now... I occaisionally use wine to play eve-online while in FreeBSD. I find the experience somewhat variable. Beyond the fact that the nvidia driver has some serious drawbacks supporting my hardware (8700M-SLI), I find that X resource usage will sometime prohibit allocation of shaders (or I think that's what fails).
I find that sometimes I have to exit some hogs first. I can almost never run eve if xchat is running. If I've been too busy with firefox, closing it sometimes helps... although unlike xchat, it can run as long as I don't have too many tabs open
On my system, I have a UFS root and ZFS for everything else.