As far I am aware about the story of my friend @Plouf ( Chris ),
he got a new UNI-T 21002cel before few days.
This scope limits him down about data logging, about to save a screen shot in the USB stick it works.
But the only software that came with it, is something that looks as remote control and not as logger.
He's question about the Rigol haves to do mostly with the possibility if those Rigol they can do more about logging in a hardware level.
( I have jumped in the topic, just to help a bit further, because Chris is a Greek too)