**"The special things, Vue allows me to do, plus handling billions of polygons - i'm not sure, if it's that easy, to keep everything perfect clean in the memory organization. It must be pretty complicated, to write the code for the program, to do all that and the same time write routines, which suppose to decide, what's still needed or not. What should be kept in storage or not. Which parts of the scene, erased or not, are still related to each other.
And all that with endless possible given situations or scenery setups ...

That you will have your memory filled with certain things after a while working and changing many different or a few heavy impact details, is logical. And if i notice, that resources get lower, well, the cleanest way really is to save the scene (then only the scene related data will be saved) and restart (taking just seconds), to get the most resources back and use only what's needed.

And - i'm not sure, if they ever will be able to work out a perfect resources routine, which can decide by itself, what to keep or not to keep in memory ...
(Just let C4D, 3DSMax or whatever the big 3D packages are called, create and handle procedural terrains and special texturing and immense plant use - and keep their memory handling clean. Since they don't use special stuff like ecosystem and whatever Vue is specialized in, than those application for sure have an easier job, to handle their resources ... and make them look good, in whatever they can do ...)."**

I have to disagree entirely.  Vue doesn't do anything "special".  It's math; it's instancing.  All of the major 3D packages have instancing, and none of them handle it as poorly as Vue does.  The high-end packages all handle memory better, especially at rendertime.  They can all handle far more vegetation than Vue.  And without bogging down or crashing.  AND, on top of that, while actually giving you the geometry you're working with instead of dodgy, nebulous wireframes that barely give you an idea where each plant is going to go.  You can even select ANY single vertex on ANY single leaf, or change the material of one leaf or all or just a few...  And proxies!  Vue doesn't even touch upon proxies, binary or otherwise.  And you don't have to restart them to get them back under control; you have full control of your memory allocation every step of the way, especially in Maya and Max.

Ecosystems aren't special at all; Maya for example has no problem painting massive plant systems on all kinds of geometry.   And also no problem handling huge datasets, billions of polys,  fractal procedural terrains or ANY kind of object, and ridiculously complex displacements.  And mental ray renders far, far faster and better than Vue's renderer, with full-on GI/FG, physcially accurate materials and caustics, and all kinds of other features.  I'm actually surprised E-on hasn't purchased MR as an optional renderer for Vue.

Simple example scene I've been working on (Maya viewport):

This scene isn't finished obviously, but a good example of vegetation-painting and instancing.

And if you want to see how realistic such scenes can get, check this thread at CGTalk:

http://forums.cgsociety.org/showthread.php?f=132&t=754315&page=1&pp=15

Example render (NOT mine, by the way!):

I'm not stating all this to say that Vue isn't a useful tool.  Vue is awesome and has MANY great features, especially when it comes to parametrics!  The skies are amazing; it takes much, much more work to make such skies with other packages.  It's much easier to start up and far easier to learn, of course.  But when comparing Vue to the major 3D packages, I just believe that you are inexperienced or uneducated on their capabilities.  There is nothing Max or Maya can't do that Vue can; there are millions of things that they CAN do that Vue can't.

Please take this post with a grain of salt... Just clearing up misconceptions; I love Vue too!