The bikes are different.
The 450 has a very good traction, revs quick,
but for me it was unusual to drive in higher revs.
I miss the punch (torque) at lower revs.
The 570 is similar to my 550- It was all familiar.
The trac was easy and flat, with some jumps, the wether fine and the earth with bestl grip.
Coming out of a 180° turn the 450 push on unspectacular, no drift or to much wheelspin, the 570 goes faster cross. But easy to control this.
Some good riders say the 450 ist the bike for races (like the GCC 2 h Crosscountry).
I have to try both in a difficult terrain.
And the 570 with the mapping choice switch, the tested was without this, means "standard"
Then I can say wether I prefer the smooth 450 or the stronger 570.
Probably the 450 will be the better, "intelligent" choice
Crazy: one the one hand i look for better handling in single trials, on the other hand I love the fun with of the big engines!
And now? who spend me money to change my 06 in a brandnew 09? :roll: