I always wonder, why people dont make stress tests especially with bigger world and more textures. In that case the review of T3D would look a bit different.

First of all I also like their scripting language and I like their tools. DTS is easy to create and very powerful. The terrain system is great also.

But when you try to create some bigger worlds you will miss some serious scene management. The portal and zones system is buggy and does not work in T3D currently. They are aware of it though. Also the advanced lighting system is quite slow compared to similar renderers. And the pureLight integration is weak. You cannot render directional lightmaps, so you cant combine lightmaps with shaders in a smart way. Also there are no light cells or similar volumes to influence dynamic moving objects by the pre-calculated lightmaps.

So in the end everything is a bit weak implemented. Dont take me wrong, it is a great engine when you want to make a small game. But this applies to 3dgs also. For something bigger than a single room you need to look to alternatives like C4, UDK, Unity or Vision3d. While the last one has most performance it is also the most expensive. But all of them can handle bigger worlds better.