I have Truespace 6 and its pretty good. Use it to make models for Bryce. If you export as 3ds or dxf, Bryce can load the models. There is a book on Truespace 4 called "Inside Truespace 4 by Frank Rivera". Cool things Truespace has 1. Different types of metaball primitives 2. Real booleans- can boolean something lots of times. 3. Can draw something freehand and extrude and bevel it. Some things you have to watch for if you are exporting to bryce: 1. If you have a model and you want to put a different texture map on each part, make sure you use the hierarchical scene manager to group them. If you don't it will be all one mesh. 2. If you make something with lots of metaballs and import it to Bryce, you end up with a lot of "mb_prims" which do nothing. Have to remove them by hand. 3. Some of the plugins may not work with Truespace 3, since the sdk may have changed. Don't know if these problems are in 3, I know they are in Truespace 6. Things I wish Truespace had that Bryce has 1. One place to see all your materials instead of having to fish around on the hard disk for them. 2. Way to save the view pos. 3. Less bugs. Don't accidentally hit the scripts button if there are no scripts loaded or its goodbye to your work session. Some actions can cause a dialog box to pop up behind the app which makes it seem that it is hung. Have to alt tab to see the dialog box. 4. Sometimes the 3d widgets are hidden or don't work so well on small things.