I know there are threads saying that higher speed memory works in the newer 2011 MacBook Pros. However, as a power user, would I actually notice any difference between say 1333Mhz and 1800Mhz RAM? None of the other threads really address this. I can buy 1333 for $29, while 1800 is nearly triple the price. Is it worth it? Does it affect the user experience at all besides increasing the geek bench scores?