I'm working on Coleco Donkey Kong now... That one has a LOT of vector points all over the place (like 20 or 30 just to make a circle) Since it's mostly a couple of sprites used throughout, I'll fine tune those and just duplicate them all over. I'm curious if the in-MAME SVG renderer will work better with a few thousand less nodes to calculate...
Beware that I'm going to work on the renderer to make its output closer to inkscape's. Plus I know how to make all that fast, don't worry about the speed.