My experience has been the same. My Tiger bark's are low/no maintenance and root so easily. My one Willow leaf makes me crazy. It drops all it's leaves around November and plays dead until April. I've never tried cuttings because I don't want any more of them.
I wanted to get one when I started, then I watched a few videos from David Cortizas, a bonsai artist from Spain that studied in Taisho-en. He worked in a few of them and constantly mentioned not to treat them like tiger bark or retusa because they will not respond the same. Even when repotting he treated them differently. I think Scott also mentioned something like this.
This is his channel, it's in Spanish, but you can use the settings and get subtitles auto-generated in English that are very close. His content is 60% or more about ficus.
Also, he is working at Taisho-en right now and has a live feed from there, I think he mentioned they will be working on some trees in preparation for the Taikan-ten... but I caught a little bit of the beginning so I may be wrong.