as other folks have replied, Z80 is more expressive and yields more interesting replicators faster. however the question of how complex to make the "base layer"

as other folks have replied, Z80 is more expressive and yields more interesting replicators faster. however the question of how complex to make the "base layer", if you will, remains open. we expect it to also be an ease of auto-evolution vs. performance tradeoff. second question is a good question :)