Bear in mind, the SC10RS was an evolution of several other trucks that have been around for years (The T3 evolved into the T4 which was stretched into the SC10, which was evolved into the SC10FT, where the setup was tested and tuned, all the while, they released 3 different RTR versions of the SC10 and finally the SC10RS. The RS may not have all the FT bling, but the box setup was certainly honed in a LOT.)

I will bet that the SC104x4 RTR would be reasonably competitive as long as you upgrade the slipper, but it won't be as competitive in 4x4 as the SC10RS is in 2wd. One is a tried and true chassis that has evolved over years and years, the other isn't even a full year old yet. It's fantastic, but it's still just a baby.