The AAM is a 2:1 bias and the trutrac is a 3:1 bias so it's more aggressive. The trutrac would better for the off roader or sled puller but an Arb would really be the best option if it's going to sled pull.
The aam or trutrac start driving both tires instantaneously, its not like a locker where there is a slight pause or a g80 where there is a great pause. Only when the traction for one tire is far greater than the other will it not longer function in driving both tires
I do not like autolockers for daily drivers. I've said many times over. They are loud, takes a different driving style and if you don't learn them, you will eat tires or find the ass end take place of the front end as it comes around on you unexpectedly in slick conditions. There is a "wind up" to then sometimes around corners and things can get interesting.
I'm not sure how a trutrac would do up front when in 2wd. You have to remember the driver side cv is always driving the diff. It may wear the worm gears out quickly. Don't really know though.
I personally like the g80 for what I do. I need a locker off road but I want nice driving characteristics on road. The next best thing/upgrade would be an arb