The Apple, Intel, and AMD memory controllers all look pretty similar in performance to me. Memory latency is the same at ~100 ns; Firestorm is clocked lower so latency is lower in terms of cycles. One Firestorm core can saturate the memory controller while Intel/AMD can't so that should be an advantage for single-threaded scenarios. Intel/AMD are behind, but I wouldn't say embarrassingly so and they haven't been lazy.