This is really a good question. I started out with a rear locker, and it was exactly like TURBO described to me once.
He came up with a scale ranking that went like this..
Out of 10 points,
Open-Open is 0
Locked rear is 3
Both Locked is 10
Of course that's not to say that just with the front locked alone its going to out perform only locking a rear, but when I was locked in the rear and open in the front, I was still getting stuck and have to do alot of different lines to get through something that now (im locked front and rear) I can go through it in reverse while doing a chinese fire drill with cartwheels.
If I were to compare the two, I would say that if you are doing alot of flat ground wheeling, maybe put the locker up front.
If you are doing alot of hill climbing or the sort, then put the locker in the rear?
just a guess
