Finally decided to upgrade my camera to D300s. When I held the camera in the store (Body Only), I was confused why people are complaining about the weight all the time. It felt about the same as my D40 to me. However, after I got home, put the battery in, put the CF card in, and attached my 18-200mm lens, it became so much heavier.
This morning I compared it with my D40 which feels almost weightless now. Make me think twice whether to sell the D40 or not.
D300s is quite a complicated camera for me (aat least for now now) with its many buttons and lots of stuff in the menu. First thing I notice is the bigger LCD compared to D40 which is very nice. Then I tried taking pictures and AF is faster and quieter than D40. Well, I need to learn a lot more now but I feel that this camera is more solid.
Anyway, I will compare pictures later. Time to study the camera now.