Honestly, besides the very vintage Nikon F50, all of my Nikon (the 4300, D70 and the D300) had been send to the service center for various kind of problem. Even though it had caused some inconvenience for me, but the service had always surprised me in all ways!
So the D300 was being send to the service center for the crack (the I actually thinks it my carelessness that caused the crack), not only that Nikon was willing to replace it for me for free, they even helped me to clean the sensor, replaced the grip (whick was still very new), cleaned it up inside out and they even fine-tune the focusing for me!
I didn’t realize that the D300 could be so much sharper and I would like to thanks Nikon for the responsiveness about their product!!