I definitely agree with this. Unless the new model is the start of a brand new line, most manufacturers change maybe 10-20% of the sounds and features each model release...

So, to get a model that is twice as good as your current, you have to wait two or three models.

Mind you, you say you have already ordered an S900... isn't it perhaps just a little late to ask this question? As soon as it arrives, you will be able to make your own decision about it!