mapping of Vertex Buffer Objects


I am converting very big parts of OpenGL 1.5 code to the Symbian platform.
This code uses glMapBuffer for often, particular changed Vertex Buffer Objects.
I know that glMapBuffer/glUnmapBuffer is not supported by OpenGL ES 1.1 because reading directly from Graphics Memory is not possible on these devices.
My question is, how to do the conversion of a code which is using this functionallity quite often. How to do this in a performantic way.
If these arrays are changed quite often, should i also use VBOs or is it faster do do it with client arrays.
Is it possible to simulate the behaviour of glMapBuffer to avoid changing big parts of code?
Anyone an idea how to handle this? Flame?

Best Regards,

Use glBufferSubData() to update the buffer objects.