I have an upgraded (ERR and a can motor) version of this loco; one of the things I like about it the most is the lack of traction tires - it will spin a bit starting a "heavy" train - just like the real thing.
Now, I don't pull 25-car trains, and I have no grades (which should be moderate, anyway) and I have 072 curves. Still, I have never found adhesion (the proper RR term; "traction" is for your automobile) to be an issue. I would like more locos without the "traction" tires. Very few 2-rail O-scale locos use them (their layouts are "laid out" more realistically).