I agree with Rudy, deep snow is the only time I miss a front locker and chains help overcome that.
If you're hard core crawling all the time you'd need a locker, but you will break lots of front end parts either way. That is why I say ARB or open in IFS, anything else is wasted money that should be going towards a solid axle if you're seriously crawling.
"Silent enim leges inter arma." -- Cicero