Our venders here on the forum have about as good of a price as you will find.
Personally, I like my lock right locker just fine. I was apprehensive at first (because I live in the snow belt) but Don (my mechanic buddy) convinced me to go ahead and put it in when we installed the 4.88 gears. I have driven in slushy snow to date... but haven't had it in deep snow or ice packed roads. But I am quite use to driving with it now and I'm OK with the thought of icy roads. On ice nothing gets decent traction. If it is cold enough, studs don't even help. You just have to use common sense and stay alert to conditions.
There are other discussions here on the forum of some members who don't care for the characteristics of the lock right. There are others who don't experience all the normal characteristics of the lock right, for instance when you coast through a turn under no power or very little power, the lock right should "ratchet' or make a ratcheting sound as the tires over ride the locker at different speeds.
Occasionally torsion builds up in the axles when driving on hard ball roads continuously and the the torsion will suddenly release with a bang (and I mean a "BANG!") as the side gears over ride the drivers to release the built up tension. It can be loud as hell... but I am good with it. Especially in drive throughs. Everyone starts looking around to see who got ass-ended. It's fun. But I have a warped sense of humor, too. Always have. Probably always will. The added traction capabilities it gives your truck, for the cost and ease of installation = a great deal in my opinion.
NO truck/vehicle can or does go through "anything". I chuckle whenever I read that line, but a locker seriously improves your probability of increased traction and normally does provide you with more mobility over open differentials providing you have decent tires for the terrain, ect.
If I were made of money, I'd opt for an ARB locker for the "convenience" and predictability on hard ball or snow. I am not and don't intend to be, so I am good with the lock right. Hell, even if i had the money, I'm such a tight ass, I probably would talk myself out of it and buy a lock right anyway.