I'm planning on getting the 13" MBA with the upgraded 8gb RAM but am unsure whether if its worth it to upgrade to keep the 1.8 i5 or upgrade to the 2.0 i7. I'll be running parallels on it (mostly microsoft onenote), but other than that, it'll be just for just basic everyday use. does parallels rely more on the processing speed or ram? most likely i'll be running about 5-6 programs at the same time. I don't have a problem paying for the extra processing speed but am worried about everyone saying that the i7 has some heat issues. having the i7 would be nice but not if its going to be significantly warmer than having a i5 processor. any advice?