Admittedly, after Seedvault appeared very unstable to me when I tried at first, in recent months (plus me changing my backup settings), my experience hast become more positive. Nonetheless, a better solution, assuming no significant drawbacks, is a nice perspective. So I had similar questions like you - and came to similar conclusions: Other issues probably demand much higher priority, atm.
In case someone acquainted with development of the future backup solution is reading this thread:
I was wondering if it has already been decided if that future solution should be backward compatible to existing Seedvault backup data?
Personally, I'd find it very useful if old backups could still be restored. Maybe you can already say something about that matter.
Thank you.