I agree with Chipperman. If you are going to compare tractors it needs to be an apples for apples comparison.
Comparing vehicles based on number of cylinders and not horsepower output is not the way to compare any motorized vehicle.
Here are a few comparisons of the Kubota 4330 and the Century/Branson 3045/4520
Kubota 4330 gross horsepower 43, the Kukje twins 48.
Kubota 4330 net horsepower 41, Kukje twins 45.
Kubota 4330 PTO horsepower 36, Kukje twins 40.
Kubota 4330 weight (GST) 3470 lbs, Kukje twins 3890 lbs.
The Kubota 4630 is the comparable model to the Kukje twins in the 3045/4520 model. The Kubota 4630 is rated at 47.2 gross hp, 44.7 net hp and 39.5 PTO hp with a weight of 3470.
I stand to bet that the price difference between the Kubota 4630 and the Century/Branson 3045/4520 is going to be more than $2100. /forums/images/graemlins/wink.gif