I was looking into picking up a 12" Pbook and I saw that the 1.33 GHz Pbooks are on sale. That plus my student discount puts it at a really good steal. For the 1.5 Ghz Pbook, I'd bee looking at another $200, but it does come with a 512 stick of ram instead of the 256, although the ram is not an issue. Is the 1.5 that much faster than the 1.33? Should I suck it up and just spring for the 1.5 or is the performace not very significant?