Whatever matches the specs that Apple gives you should be fine. A name brand will be less likely to fail DOA than a no-name module. For notebooks, there's usually not much you can do to improve performance, because of limited ability to modifiy settings. If your notebook can run memory in dual channel mode, then that will require a *pair* of identical modules(in speed, latency, size, and organization), but can boost the memory throughput 2x.