Henni,
You are most welcome !
I would advise you not to take a fast decision unless you can buy one of them at a very attractive price.
The S770 and S970 were launched in 2015, as you might remember.
For the time being our local dealers are lowering the complete S-serie price.
I would absolutely not be surprised the successors will follow mid 2018.
Nobody knows, except Yamaha, what the new models will bring us and when we can expect them in the market.
The new models might be introduced much sooner than we probably think.
The brand new Korg PA-700 and the new PA-1000 are very strong competitors. Great keyboards, really !
I am almost sure Yamaha, being an important Korg shareholder, cannot wait to bring their answer in the market very soon.
It is my intention to go for the S770 successor in the near future. Not too soon. I bought a new S-770 in April 2017.
Since last week I have added a brand new Korg PA-700 to my configuration.
A great keyboard but completely different than a Yami, as you know.
In our local shops the PA-1000 will be available soon.
We might find some Genos features in the new S-serie, IMHO.
A touch screen too, maybe ? ... who knows.
There will be a small price increase, as usual, I guess.
Best wishes, Jeff