I tried S670 yesterday again at store and it seemed again like a great deal. It sounds like it has a lot of "S.Art!" voices from 700/900 series, but without "S.Art!" algorithms. Comparing to PSR-S950 it sounded rather close overall.
I also tried Korg PA-1000 and a little bit PA4X (oriental version). I'm not going to say that S670 sounds the same or better, but with Korg I was expecting something like "just touch it to know the difference" given its cost, and I didn't come to a certain conclusion. But I guess a more accurate look may reveal a lot of nuances.
In the end I have to conclude that any keyboard demands a real amount of time to get focused on it, after that it gets really usable rather than just entertaining.
Edited by Kabinopus (03/10/19 01:50 PM)