Wonder this myself, didn't make a lot of sense when you see the entire line has been updated with t-loc. Does anyone have inside information on why Tanos came out with the T-Loc? I examined both boxes and I have come to my conclusion that the T-Loc is cheaper to manufacture. The T-Loc is less rigid and has less moving parts. The larger versions of the T-Loc are sort of weak and wrack even.
This leads me to think it was a cost cutting measure and a way to increase profits more than a way to improve the ecosystem. For the cost and the clientele you would think the new ones would be a little heavier duty.
I personally like the way the T-loc works better, the single way of stacking them with the lid and the fact that they made both of them work together is fantastic. Just wish they were a little more heavy duty (especially the handles) and also wish they had made the sortainers all t-loc.