Personally, sound, editing, & style wise I'm truly satisfied with what is on the market in arranger KB's TOTL/MOTL technology right now, ... Let's face it, how good do you think it's gonna get in the future that you can't already do with any of these models right now? For my needs, I can pretty much play just about any song I need to perform with what I already have, yea a few new FEATURES would make life easier but not essential using some workarounds, or would change what I can do with these amazing instruments as they are now. If they never make another arranger I could live with what is already available.
I think too much emphasis I put upon OTB sound then what can be done if you dig into the OS if needed many don't try or know how which is sad.. IMO no matter how good these instruments sound it's the player that has to make them shine, that's where the emphasis should be always. What do you think?