For those interested: a new firmware is out, version 5.10.1.0. This brings the new RTO6 user interface to the older RTO2000 and RTP scopes.
Maybe also interesting to know is that the older hardware modules for the MSO and for the function generator still work on the RTO6. So if you are upgrading from an earlier RTO you can re-use those modules in the RTO6. The only thing that has changed about them seems to be the order code.