The 450 is an interesting motor:
very soft on the very bottom yet starts to build torque quickly thereafter
revs fast like a 2 stroke
at first feels like it may need more flywheel weight yet does not stall
no noticeable hit, very smooth
feels like a 250 two stroke with no hit and a lot of compression braking
huge change in power delivery compared to my 01 470 which has almost too much of a
bottom end hit
my first impression was that the motor was not very fast due to that lack of hit as soon as you crack the throttle, now I appreciate the smoothness and control this motor offers and wouldn't want it any other way.