gschup
Sapling
Thoughts?
Love the ume's by the way.
I am not questioning Andrew's expertise or experience, I am very sure he is extremely proficient and knows what he is talking about: That said, I don't think you should be discouraged by this video. Andrew works with his stated goal of working with the "highest level decidious bonsai". I am assuming that means he is aiming to create and refine highest level of bonsai in his lifetime. Andrew says the tree featured in the video "feels lacking". This gives valuable perspective for his ambitions. If I had a grown a tree like that, I would be very satisfied with the result.
While not mentioning them specifically, Andrew speaks about the complications of working with this species. Those seem to be very real and are reported everywhere on the web and in books. But if you just want to grow a cool little ume tree in a pot, there is absolutely nothing that should stop you. Bonsai is a hobby and if this is what you want to do with your free time, you should do it!
What I dislike about the video is that he talks about "a roadmap not existing", but he never explicitly goes into details of why that is and what the limiting factors are. I do like his point of other prunus existing that are easier, quicker and more forgiving to work with.
Finally, it seems to be very possible to grow quite impressive results, as shown in the video. It might not be good enough on the highest levels of professional bonsai, but it for sure would be good enough for me