There have been many internet discussions and disagreements about the use of traction tires on locomotives.  USA Trains seems to use them on all their diesels, except the NW-2 and the new S-4.  Aristo used them on their RDC and also on some their four wheel truck diesels for a short time.  This practice was discontinued due to numerous customer complaints. We will never see rubber traction tires on any new Aristo products again according to their production people.
    USA seems to love traction tires, and it looks like they will continue with this trend on their new diesel releases in the future.  I have heard both sides of the argument for traction tires, and have done a short informal survey.  While traction tires do increase traction by gripping the rail more than a solid metal wheel would, you sacrifice power pick up from these wheels due to the rubber insulation. To counter this, USA has provided sliders to improve power pickup.  The downside of these tires is that they do not let your wheels slip when your locomotive is overloaded, due to grade or large number of cars.  As a result you may sacrifice your gear boxes, which is an expensive repair that not all can accomplish at home.  The tires themselves have a tendency to dry out and crumble requiring replacement. They also may leave residue on your track which may cause additional power pickup problems when they heat up especially on outdoor track that gets hot in the sun. This problem is similar to that caused by plastic wheel sets on outdoor track.   If you run outside, have grades, or run long trains, I would recommend changing your traction tire wheels to solid wheels.  I have done this on all my diesel locomotives with very little degradation in pulling power.  For level layouts, or layouts that are indoors with no grades, the traction tires should cause no problems.