Matt
Either the second model with the locking ring, or the BR-D would be supperior to the non locking ring model only in that they do have a locking ring. The internals, while a tad different in all of the models, are equally functional.
One thing about some of the locking ring models, they can have a lot of slack in the threads that make up the objective lens assy. That means you adjust it, but when you lock the ring, it goes out of adjusmemt. That simply means you have to get all of the slack out of that objective assy, sometimes it takes a little trialand error.
No matter which you buy, you can just send it to Leupold and they will check it out........jackie