Locker
I have a lockrite in the front 10b on my K5. It wasn't my first choice, but I discovered my truck has a limited slip in the rear 10b. Ive only off road with it a couple of times and I like it, but it does suck trying trying to turn onto trails or tight spaces.
This last winter it really got a work out, we got hit pretty hard (compared to the last five years). I was reluctant to use the locker because of the difficulty making turns with the locker in the front. So most of the winter I didn't use it. When I did, slow crawls on highways (15 to 20 mph) it worked great, never a major issue. The only time I was stuck it was on a 40degree hill, and that was mostly because of my tires getting filled with snow, than the locker. I would like to have a selectable, but the lockrite was pretty affordable.