> and in general PS2 "Graphics Synthesizer" is kind of fast but very simple texture
> unit, also it don't have kind of exclusive features, so its not too hard to emulate
> it on hardware or even on software (with a lot of smart otimisation of coz)
Correct. PS2's GS was purely a brute force part: it could draw bilinear filtered polygons very very quickly, and that's about all it could do. No bump mapping, no advanced filtering, no shaders, etc, etc. Clever programmers were able to simulate many of those features, but of course that was part of what made the PS2 famously hard to develop for.
PVR2 was more like modern GPUs: less brute force, more clever features, and so it takes more capabilities to emulate properly.