I've had a lockrite locker in front for years, never broken a shaft but I'm easy on the skinny pedal. Bottomline, the worst mod that I have ever done on any vehicle, can't turn for squat! If you don't want to listen to these folks about the only option is to go selctable in front than I would highly suggest don't lock it at all. Now that I have seen a few rigs in only locked front wheel drive on the trail, and the fact that I have selctables in both ends of my Rubi, a front locker is far over rated.

1995 Honda Passport;
Some people wait a life time for their ship to sail in, while others simple grab the oars and begin paddling
Yours truely
http://www.zutah.com