I don't want to start a tree rivalry either, so I'll leave it at that.
Here's my overall criticism of Speed Trees. For the most part, no matter who makes them, they're always too big and clumsy, too clean, and too perfect. It's for this reason, I think, that we tend to use more than we really need while trying to achieve the textures and thickness that real trees offer, and this was where the old flipboards worked because they were thin enough and light enough to fill an area, yet not completely overpower the scene at the same time. The Speed Tree objects are great for lawns and parks, but not really suited well for a forest. No matter how much we try, we can never quite get that real forest look.
I never look at trees in a scene as being just trees. The tree objects, like other objects on the route, make up the composition of the scene and should add rather than detract from it. An old Victorian house for example set up with some old oaks and birches placed in clumps can really add to the realism of the scene we're trying to achieve. With Speed Trees this becomes quite an effort because of their size, shape, and coloring. Not all trees are 60 to 80 meters tall, and have a circumference of 80 meters around them with the branches. Not all the trees are the same color either. The creators have done a great job, with the tools they have, but overall they all have either a very dark green or a drab olive green which really isn't right. If we look at real trees, we can see that they not only vary in shape, color, and size. The juvenile versions of a species don't always look like their grown up ones either. In most cases they're not just thinner, but their branches are shaped differently as well.
Many of these issues, I think, is the fault of the ST developer engine used to make the objects. Perhaps in the future the developer can update their toolsets to achieve the level of realism we wish to have. It's too bad we couldn't adopt some of the other tree and plant creating engines and programs which I think make much better looking trees than Speed Trees never can match at this point in time.
Plant libraries and procedural trees.
http://xfrog.com/
http://onyxtree.com/
http://www.digi-element.com/vpm/index.htm
I have used the plant mechanic that is built into World Builder. It's quite interesting to generate "species" of trees and plants using their cross-breeding engine. For this program you "grow" your trees and place them in the scene.
None of these programs is cheap, but then again neither was Speed Trees. I only hope that N3V had looked various products before settling in on Speed Trees for their use in game. Granted the animated trees are an added "feature" with Speed Trees, but I'd rather have decent looking trees than ones that blow in the wind.
John