I agree to both of you. So in the end GS (actually Lite-C) is a good multimedia-programming language. You can learn a lot on different levels (from easy coding up to shader coding). This can be good for prototyping as well.

But all this becomes another story if you want to finish something. Engines like C4 don't let you program shaders for good reasons. C4 delivers a graphical shader editor with nodes. The reason is simple: If you use this tool then all shaders are cross-platform and work with shadows, all lights, fog, post-processing and whatever feature else appears. Hand made shaders in a language like HLSL easily explode in their variations and numbers to support all this. And this is not a task for a game developer, it is a task for a specialist.

This is only one example and the same counts for the tools, real-time editing, shading, physics and scene-management.
It is a great relief to have such tools at your side.

I also agree that it might be easier to start with Lite-C than with C++. But in the end you lose time when you have to write shaders and when you write a lot of procedural code without classes, without inheritance. If you reach a certain point of complexity then the final game code becomes difficult to read in a C language. That is the reason why they invented the object oriented approach and why every modern language uses it.

So what is left is a nice multimedia language in C-syntax with a few old-school tools. Not bad for this low price. And even better for free (the free Lite-C edition). It will help many people to learn and to jump later to some other tools, to switch later to advanced programming languages and to get into 3d applications. It is a nice transition stage and you can finish some small games.

But to come back to the original topic: T3D is clearly directed to the professional developers. They try a lot to optimize the engine. They include ready working shaders, shadows, post-processing, scene-management and other needed functionality. And - this is very important - they make games themselves with this technology. They find the weak spots early and can do something to improve this.

The same counts for Unity.