We (OK, our main client) migrated this year straight from 10. We do have some issues with NLS and varchar2(4000) fields, date fields and xml's. Otherwise no problems.
I would rather do APEX but legacy is legacy ...
On the other hand I am researching / learning / taking two paths. First is WordPress - no programming, just setting up, fidgeting with themes, and running. Second is all blockchain (whatever variety) related stuff. The real future.
I'm playing around with Python for fun. Want to try coding stuff around the Steem blockchain, even if it's just for my own interest