Originally posted by ducdao I thought the Nikon 7100 was meant to be the successor of D300/D300s series.
Nah, Nikon butched it up by giving it crappy fps, which the Pentax D400 delivers in spades. Nikon likes to play this game they eliminate one or two critical functions out of a lower tier camera body so that you buy the higher one. Sometimes these issues could be addressed by firmware, but they have a history not to do this kind of updates.
If your ideal camera is the D800, you're in luck, otherwise your camera is probably not going to be perfect.
I feel that Pentax OTOH always give their customers their very best effort in every camera body for a given price point.
At the moment D700 (low MP high FPS FF) and D300s (high FPS pro built DX) have no true successor. The K-3 is through and through a D300s successor, other than the pentax logo and K mount.