Hmm might just be you and me left in MAMEland, Bazza. Everyone else moved on to the flashy console emus. I finally found a working version of R-type and get 86% after the slow start you mention, and i've got an 805MHz clock. Something besides CPU speed is the limiting factor (or my N900 needs a reboot, which isn't unlikely). Memory bandwidth, i suspect... Seems very playable at 86% with the default frameskip, though.