Accelerator cards

breaking compatibility with previous generations is a logical thing. PS2 to PS3, tapes to CD's, etc. Sometimes, you simply don't want to keep dragging the limitations of older systems forward. It's also the choice of the owner of the hardware. After all MSX is a hobby and we shouldn't be held back by legacy of the 80ties if we want to move forward.

So in terms of getting the most out of the MSX what is the best cartridge? Gr8net?