I did a comparison between Thunder, Indy, and Ace on like the dryest possible curb in front of my house.
The Thunder will not budge at all.
The indy grinded, but it was sticky.
The Ace went through basically no problem.
So Ace trucks definintely have a faster grind than anything else. If I put the tiniest bit of wax on it though, the Thunder grinds no problem. I would say when I do lock in on thunders, even on a 5050, it feels a lot more stable than those 2. I locked in a 5050 on a very square curb where both toeside wheels hugged the inside of the curb and it felt like I was just standing on flat. I just sat in that grind all the way until the curb ended like it was nothing.
Its possible the Thunders need to be worked in a bit more but I feel like that type of metal just doesnt grind as fast, and that's ok! you just need to wax it a bit more and it actually feels really awesome and solid.
The noseslide dragging thing kinda bugged me at first but I think it actually makes for a more solid, predictable noseslide!