Wine touches big parts of opengl drivers which 'normal' apps don't touch and we use most recent 3d features. The intel drivers are still very young and don't support various of the modern gl features well (e.g. poor glsl support for shaders, and so on). The issues you are seeing are a result of the driver quality. A game like quake3 is too basic compared to what Wine all touches even for simple apps. In case of soldat the use of RenderTargetLockMode=readtex could help a bit (if the game is using 3d stuff behind its back since glDrawPixels/glReadPixels performance is very poor on intel).
