I had an arranger for many years and changed to CVP. I now have two - a 605 and a 705. This may seem a bit over the top, but its because I have two homes, and have everything duplicated, including my grand pianos. I do not know what will be in the 800 series, but probably just a few improved sounds, and a few additional arranger features. Like I said on another thread, these technologies are now so mature all changes are incremental, and never a huge difference.
My playing nowadays is mostly two handed piano with simple style accompaniment. The CVPs are both perfect for that. The only significant difference between the 605 and 705 is the additional piano voice sample from the Bosendorfer on the 705. The 705 also has the piano room accompaniment feature. It was a bit of a nice novelty for a while, but in all honesty, I seldom use it now.
Occasionally I drop into full arranger mode, and find the CVP does everything I need, nothing missing from the arranger or recording features I would desperately want. I have found that styles are pretty interchangeable ie Tyros styles ( and I suspect Genos styles) will play on the CVP. Like all model changes, you might need to tweak the voice choice with style imports, but not much.
Everything really depends on what you want to do on the keyboard, but I would say that the CVP is everything most will ever need from an arranger as well as a nicer piano. Of course it cost a lot more even that a Genos, although you might get a used CVP700 or 600 at a very good price and in perfect condition. People buy these things because they live in a dream that they will be able to be great players in a few weeks, then reality sets in, and a couple of years later they are for sale almost as new.
One thing I would say - the 709 and 609 difference is only the keyboard feel. And the cost difference from the 605/705 is quite a lot. I am an ex pro piano player, and while to me there was a detectible difference, it is not hugely noticeable. Unless you are a top class concert pianist playing Chopin, it may not be worth it.
Mike