I'd like to get some ATW for improved Winter performance compared to my AT3.
However, I like my AT3 a lot (outside of Winter conditions). My AT3 are good about not picking up gravel. They occasionally retain gravel, but not much.
When I had BFG AT KO2 they picked up (and retained) lots of gravel. The General Grabber AT2 I had were the worst for picking up and retaining gravel.
When I had all season tires they never retained gravel. Same when I had MT. I guess very small voids (all season) and very large voids (MT) are the only ones that never retain gravel. Medium size voids (AT) are prone to picking up gravel.
Warning: I often edit my posts a few times to get them complete or correct errors.