I don't see any reason to replace your Roo 21SS with either of these models. Of the three I prefer the one I bought: Roo 23SS.
We have a Roo 23SS and (like the 21SS and 23IKSS) it only has two beds. Massive amount of galley counter space only exceeded by the 23ikss center island. We have the standard booth dinette like you have (current model has a U-dinette).
We do NOT like the lack of access in the IKSS on the road. Can't get to the bathroom etc. 'cuz the slides block all access. The 23SS bathroom, refrigerator, galley, etc. can all be used with the slide in.
I really think you need a 3 bed model for the foreseeable future and that third bed precludes a large galley or slide. Just so much you can do in this size box.

-- Chuck