I've been following this for a few years.
The thing to keep in mind is that it is, and probably always will be, an archival storage method, not a working memory method. Storage and retrieval is slow.
The big wins are that
- storage density is very high
- stability is very high not because the DNA doesn't break down, but because it can be created to replicate
Many years ago (15, maybe more), when people first started working on this, I kept trying to envision a science fiction book where one of the main characters would be The Librarian who would live in his library, which used giant sequoia trees for storage. Slime mold would certainly work better, but make a worse story. I never could get past that first, basic idea though