We bought a second hand AS from 2007 and it is amazing that, really, not a lot has been changed in terms of layout. It just proves that AS just keeps on improving on a winning design. We looked at the KK and AS and decided for the AS, mainly because of the swing out kitchen. If you have the full annex up, it creates a more natural walking area from the annex to the door and it would have become a hindrance if it did not swing to the side. We also thought that the KK had some minor annoyances and finishing issues for us, but that could be personal preferences and nit-picking. Also, we did not find even a single negative comment on the AS - all comments were just positive!
In the end, we could not fault the AS in any way, and are very happy with our second hand one. A great product and absolute quality that lasts!