I agree with expeditionswest.
But if you have friends with limited slip diffs in the front of their rigs, ask for some wheel time. This is obviously the best thing as everyone feels a little different about traction differentials up front, and responses normally vary wildly.
I will say that I have used automatic lockers in the front and rear (aussie lockers) and it wasn't all that bad in most cases. No I haven't used a front limited slip so my experience isn't 100% relevant either.
I love an automatic rear locker (using one in my current truck), but the front is kind of a love/hate deal. It is drivable in snow. Yes, the truck wants to go straight when you are in 4x4 and on the throttle. When you are maneuvering on the light snow, it is easier to run in 2wd, and switch to 4x4 as needed. In deep heavy snow it isn't as much of an issue.
Off road, the steering becomes very tight in 4x4. So working around tight trails can become a pain. The truck is very capable but you always worry about breaking something up front. I always carried a spare CV shaft, gear oil and the tools I needed to swap one out. I will also mention that an aussie locker is basically transparent with no torque applied (in 2wd). Even though my last truck had live axles up front (no hub disconnects), there was no effect on steering or drivability in 2wd. A limited slip might tighten the steering even in 2wd, at least to some amount.
On my current truck I seriously thought about running a limited slip up front because it would (in theory) be easier on the front end than a locker. And after all, there is more weight up front so the front tires are more likely to stay planted. In the end, I decided to run a rear Detroit locker since my experience says that having a good rear locker is an incredible help in the traction department. It felt more capable with only a rear locker in 2wd than it did in 4x4 with open front and rear differentials. For the front, I went with an E-locker. This way there is very little stress on the front end components during normal 4x4 operation, and the steering is normal, but I can fully lock it when I really need the traction.
Opinions vary a lot about this too, but for an IFS rig, particularly with a light rear, your money goes a lot further if you lock the rear end first (if you haven't already) before spending any money up front.
