Sometimes skills is one thing, especially if u can grow old and improve yr skills with that good camera; but needs is a another.
If yr camera is limiting yr needs, then u hv a reason to change.
E.g. u need to shoot landscape 80% of the time, then the last thing u want is to have your images cropped off; best to upgrade to FF.
Anyway, a D3 or D700 is more suited for low light. So don't waste time on a D90, else u need to go through another upgrade exercise and endure your friends' "advice" another time.
If yr camera is limiting yr needs, then u hv a reason to change.
E.g. u need to shoot landscape 80% of the time, then the last thing u want is to have your images cropped off; best to upgrade to FF.
Anyway, a D3 or D700 is more suited for low light. So don't waste time on a D90, else u need to go through another upgrade exercise and endure your friends' "advice" another time.

basically I believe skill is still vital no matter what... and if ur skill/need matches what camera u hv then its great. If u dig my other thread, i asked about D90 as i see limitation in 450D taking indoor photos at night ... where currently i am exploring if a D90 will help or not. This is purely not "wanting" something of higher spec, rather i hv specific reason and i am researching on it. if its not worth it (like other hv suggested) then i will go try other means (flash, F1.4 lens etc like what been suggested)