our local track combines usvta and usgt into one class as scale spec. i kind wish they would separate the two classes so we could use the usgt ride tires. for now we are limited to just hpi d compound tires. ive tried the xpatterns ans find them fast but twitchy and makes the car harder to drive. the vta tires are much smoother to drive but a little slower. i prefer the usgt class but there are no plans to separate the classes out, even during the summer racing season. its a bummer as ide like to use the usgt spec tire.