A few initial observations and comments.

This is going to be significantly better than Speedtree in terms of versatility. That is, the ability to create more kinds of plants.

The ability to make deciduous leaved plants with full leaf geometry and with fractal processes is a great scientific and technological step forward. Probably more than most people realize.

The learning curve for most people for all but the high-end versions will be pretty decent. Almost everything that most people will want is presented and controlled by clearly labeled sliders.

In fact, the user interface is very well designed. Not too much resmblance to what is in the current YouTube videos - much more advanced than what was shown there. The layouts are great. A lot of thought has gone into where different kinds of families of functions should be placed. The hierarchy of processes and the ability to drill down into relevant details is wonderfully clear.

There ar little problems, even with that though. I want the ability to zoom in on particular elements of a tree, for example the roots. But there do not appear to be mouse controls for that. General panning and zooming in and out  are OK, but one cannot control the vertical or horizontal point of focus to zoom into a given area.

People are asking about some features, such as the ability to respond to wind.. It is in there Lots of wind controls. The sample trees are great, at least in my humble opinion. Some are not botanically correct, at this writing, but others, such as the banana tree are purely lovely!

There are some other basic things that have not been discussed earlier, but that are of great significance. For example, the geometry is exclusively triangles. no quads. This affects and will disturb people in the model-building communities who must do post work on plant models, but it might be of no concern to most ordinary users.

One of the great features of Speedtree is that every genrating function is available at the equation (expression) writing stage and there is a nice expression editor in the program. But, this can lead to problems, as hundreds of expressions are used to contruct various properties of the plants. Sometimes, these expressions cn interact or cancel out each other's effects. It takes a lot of learning and experimentation to learn where these conflicting equations and expressions are located.

From the little I've seen of The Plant Factory, this is never going to be a problem. There is a very nice independence of function throughout the plant editor. This means that a ruthlessly systematic and clean architecture was devloped for the tool prior to actual programming and development. This is going to be a powerful application with a nice foundation for further development over time.

 

There are some issues forming about which features should be in which versions at the higher end - the more advanced versions. These issues probably won't trouble most people, and will be resolved about the time the program is realized in full form. The artist versions aimed at the casual user probably will be quite good, and a good investment for the money.