To answer your original question, the WRAM will give you slower video than SDRAM, WRAM is Windowed Ram, which is EDO memory "double ported", which means it can be written to and read from at the same time. This speeds up video functions, but as EDO memory is already much slower than SDRAM, it doesn't improve matters by much.

You should find your screen image clarity good with the Matrox, which will probably justify your decision to keep it for now. Other cards like the Voodoo will be faster, but Matrox is hard to beat for image quality.