With the exception of engines and engine horsepower and of course color and branding, the 590R and the 600 are the same machine! They have the same feeding, threshing, separating, cleaing, grain handling, grain tank, the 590R has a wide spread chopper (up to 42' spread pattern) for use with the wider North American heads. The 590R does run much larger headers though, up to the 12m (40') platforms and a 12m (40') 16 row cornhead weighing nearly 5.5 tons and the 590R will still do nearly 6 miles per hour with that corn head in high yielding corn.